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58 results on '"Centro de Física e Investigação Tecnológica [Lisboa] (CEFITEC)"'

1. Observation of Transient Anions which Do Not Decay through Dissociative Electron Attachment: New Pathways for Radiosensitization

Author: Ana Isabel Lozano Martínez, Fábris Kossoski, Francisco Blanco, Paulo Limão-Vieira, Gustavo Garcia, Marcio Varella, Consejo Superior de Investigaciones Científicas [Spain] (CSIC), Centro de Física e Investigação Tecnológica [Lisboa] (CEFITEC), Departamento de Fìsica [Lisboa] (DF), Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA), Laboratoire de Chimie et Physique Quantiques Laboratoire (LCPQ), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Fédération de recherche « Matière et interactions » (FeRMI), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Universidad Complutense de Madrid = Complutense University of Madrid [Madrid] (UCM), Instituto de Fisica da Universidade de São Paulo (IFUSP), Universidade de São Paulo = University of São Paulo (USP), University of Wollongong [Australia], Ministerio de Ciencia e Innovación (España), Ministerio de Ciencia, Innovación y Universidades (España), Consejo Superior de Investigaciones Científicas (España), Fundação para a Ciência e a Tecnologia (Portugal), Conselho Nacional de Desenvolvimento Científico e Tecnológico (Brasil), Fundação de Amparo à Pesquisa do Estado de São Paulo, Lozano, Ana I., Kossoski, Fábris, Limão-Vieira, Paulo, and Varella, Márcio T. do N.
Subjects: Anions, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Nitroimidazoles, ESPALHAMENTO DE RAIOS X A BAIXOS ÂNGULOS, General Materials Science, Electrons, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Physical and Theoretical Chemistry
Abstract: 8 pags., 3 figs., Low-energy electrons (LEEs) can very efficiently induce bond breaking via dissociative electron attachment (DEA). While DEA is ubiquitous, the importance of other reactions initiated by LEEs remains much more elusive. Here, we looked into this question by measuring highly accurate total cross sections for electron scattering from 1-methyl-5-nitroimidazole (1M5NI), a model radiosensitizer. The small uncertainty and high energy resolution allow us to identify many resonant features related to the formation of transient anions. In addition to novel insights about DEA reactions through the lower-lying resonances, our key finding is that the higher-lying resonances do not undergo DEA, implying alternative decay channels with significant cross sections. In particular, dissociation into two neutral fragments is probably involved in the case of 1M5NI. This finding has direct implications for the understanding of LEE-induced chemistry, particularly in the fundamental processes underlying the radiosensitization activity., This study has been partially supported by the Spanish Ministerio de Ciencia e Innovación (Project PID2019- 104727RB-C21), Ministerio de Universidades (Project PRX21/00340), and CSIC (Project LINKA20085). A.I.L. and P.L.-V. acknowledge the Portuguese National Funding Agency (FCT) through research Grants CEFITEC (UIDB/ 00068/2020) and PTDC/FIS-AQM/31281/2017. M.T.d.N.V. acknowledges the Brazilian National Council for Scientific and Technological Development (CNPq, Grant 304571/2018-0) and the São Paulo Research Foundation (FAPESP, Grant 2020/16155-7).
Published: 2022
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2. A combined experimental and theoretical study of the lowest-lying valence, Rydberg and ionic electronic states of 2,4,6-trichloroanisole

Author: L. Carlini, Robert Richter, Lorenzo Avaldi, Sarvesh Kumar, Paola Bolognesi, S.V. Hoffmann, Denis Duflot, Paulo Limão-Vieira, Michael J. Brunger, Nykola C. Jones, Centro de Física e Investigação Tecnológica [Lisboa] (CEFITEC), Departamento de Fìsica [Lisboa] (DF), Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA), Physico-Chimie Moléculaire Théorique (PCMT), Laboratoire de Physique des Lasers, Atomes et Molécules - UMR 8523 (PhLAM), Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Centre for Storage Ring Facilities [Aarhus] (ISA), Aarhus University [Aarhus], Istituto di Struttura della Materia (CNR-ISM), Consiglio Nazionale delle Ricerche [Roma] (CNR), Elettra Sincrotrone Trieste, College of Science and Engineering, Flinders University, Dept. of Actuarial Science and Applied Statistics, UCSI University, Portuguese National Funding Agency FCT: Grant PD/BD/142831/2018, PLV the Research Grants CEFITEC ( UIDB/0 0 068/2020), PTDC/FIS- AQM/31281/2017, Radiation Biology and Biophysics Doctoral Training Programme (RaBBiT, Grant PD/00193/2012 ), UCIBIO (Grant UIDB/04378/2020), Région Hauts de France, the Ministre de l’Enseignement Suprieur et de la Recherche (CPER Climibio) and the European Fund for Regional Economic Development, HPC resources from GENCI-TGCC (Grant No. 2020–A0050801859), Centre de Resources Informatiques (CRI) of the Université de Lille, Australian Research Council: grant #DP180101655, ANR-11-LABX-0005,Cappa,Physiques et Chimie de l'Environnement Atmosphérique(2011), ANR-16-IDEX-0004,ULNE,ULNE(2016), European Project: MD-GAS, and National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR)
Subjects: Materials science, 010504 meteorology & atmospheric sciences, Photoemission spectroscopy, C-7 H5Cl3O, Photoabsorption, Ionic bonding, Electronic excitation, 7. Clean energy, 01 natural sciences, symbols.namesake, X-ray photoelectron spectroscopy, Ab initio quantum chemistry methods, Vibrational excitation, Physics::Atomic and Molecular Clusters, Spectroscopy, 0105 earth and related environmental sciences, Radiation, Valence (chemistry), Synchrotron radiation, Photodissociation, Photoelectron spectrum, TCA, Atomic and Molecular Physics, and Optics, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Atomic electron transition, Rydberg formula, symbols, Rydberg series, Ab initio calculations, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Atomic physics
Abstract: We investigate for the first time the gas-phase lowest-lying valence, Rydberg and ionic electronic states of 2,4,6-trichloroanisole (TCA) using synchrotron radiation for photoabsorption and photoelectron spectroscopy. The high-resolution vacuum ultraviolet photoabsorption spectrum, in the 4.0-10.8 eV energy-range, has been measured with absolute photoabsorption cross-sections and, thanks to novel ab initio calculations of the vertical energies and oscillator strengths, an assignment of the electronic transitions is comprehensively reported. The assignment of weak vibrational features in the absorption bands of TCA reveal that the ring and C-Cl stretching modes are mainly active. In the photoelectron spectrum the lowest 18 ionic bands, between 8 and 30 eV, have been observed and assigned using the first set of calculated valence and outer valence vertical ionisation energies. Finally, the measured absolute photoabsorption cross sections have also been used to estimate the photolysis lifetime of TCA in the upper stratosphere (20-50 km). Crown Copyright (C) 2021 Published by Elsevier Ltd. All rights reserved.
Published: 2021
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3. Mapping the complex metastable fragmentation pathways of excited 3-aminophenol+

Author: Rahul Pandey, Paulo Limão-Vieira, Nigel J. Mason, J. C. Poully, Andre Rebelo, T. da Fonseca Cunha, Samuel Eden, Janka Bockova, M. Ryszka, Protea Atlas Project, South African National Biodiversity Institute, Department of Mines and Geology, National Seismological Center, Centro de Física e Investigação Tecnológica [Lisboa] (CEFITEC), Departamento de Fìsica [Lisboa] (DF), Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA), Centre of Molecular and Optical Sciences [Milton Keynes] (CeMOS), Department of Physics and Astronomy [Milton Keynes], The Open University [Milton Keynes] (OU)-The Open University [Milton Keynes] (OU), Centre de recherche sur les Ions, les MAtériaux et la Photonique (CIMAP - UMR 6252), Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Caen Normandie (UNICAEN), Normandie Université (NU), Department of Physics and Astronomy [UCL London], University College of London [London] (UCL), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), and Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Hydrogen, [PHYS.PHYS.PHYS-BIO-PH]Physics [physics]/Physics [physics]/Biological Physics [physics.bio-ph], chemistry.chemical_element, 010402 general chemistry, Mass spectrometry, 01 natural sciences, law.invention, Ion, Fragmentation (mass spectrometry), [CHIM.ANAL]Chemical Sciences/Analytical chemistry, Reflectron, law, Metastability, Ionization, Physical and Theoretical Chemistry, Instrumentation, ComputingMilieux_MISCELLANEOUS, Spectroscopy, Chemistry, [PHYS.PHYS.PHYS-ATM-PH]Physics [physics]/Physics [physics]/Atomic and Molecular Clusters [physics.atm-clus], 010401 analytical chemistry, Condensed Matter Physics, 0104 chemical sciences, Excited state, Physical chemistry, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], [CHIM.RADIO]Chemical Sciences/Radiochemistry
Abstract: This work applies the technique of mapping ion detection using a reflectron mass spectrometer against flight-time and reflection voltage to elucidate the complex metastable fragmentation pattern of the biomolecular ion 3-aminophenol+ (3-AP+, C6H7NO+). Multi-photon ionization experiments revealed the excited ion's fragmentation routes for the first time and comparisons with calculated flight-times enabled 18 different μs-timescale dissociations to be assigned. These included the rare observation of a double hydrogen loss channel from a fragment ion. DFT calculations provided further insights into the most prominent apparent fragmentation sequence: 3-AP+ (m/z 109) → HCO + C5H6N+ (m/z 80) → CNH + C4H5+ (m/z 53) → C2H2 + C2H3+ (m/z 27).
Published: 2019
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4. Excited States of Bromopyrimidines Probed by VUV Photoabsorption Spectroscopy and Theoretical Calculations

Author: M. Mendes, Rodrigo Rodrigues, Søren Vrønning Hoffmann, João Pereira-da-Silva, F. Kossoski, F. Ferreira da Silva, A. I. Lozano, Nykola C. Jones, João Ameixa, Centro de Física e Investigação Tecnológica [Lisboa] (CEFITEC), Departamento de Fìsica [Lisboa] (DF), Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA), Groupe Méthodes et outils de la chimie quantique (LCPQ) (GMO), Laboratoire de Chimie et Physique Quantiques (LCPQ), Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC), Department of Physics and Astronomy [Aarhus], Aarhus University [Aarhus], Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Laboratoire de Chimie et Physique Quantiques Laboratoire (LCPQ), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Fédération de recherche « Matière et interactions » (FeRMI), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), CeFITec – Centro de Física e Investigação Tecnológica, and DF – Departamento de Física
Subjects: Models, Molecular, Ultraviolet Rays, QH301-705.5, 010402 general chemistry, 01 natural sciences, Catalysis, Article, Physical Phenomena, Inorganic Chemistry, symbols.namesake, 0103 physical sciences, Biology (General), Physical and Theoretical Chemistry, Spectroscopy, halopyrimidines, Lone pair, QD1-999, Molecular Biology, Radiosensitizers, Physics, 010304 chemical physics, Molecular Structure, valence and Rydberg states, Organic Chemistry, Time‐dependent density functional theory, General Medicine, Time-dependent density functional theory, Models, Theoretical, Halopyrimidines, Antibonding molecular orbital, 0104 chemical sciences, Computer Science Applications, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Chemistry, time-dependent density functional theory, Pyrimidines, Absorption band, Excited state, Valence and Rydberg states, Rydberg formula, symbols, Density functional theory, Spectrophotometry, Ultraviolet, radiosensitizers, Atomic physics, VUV photoabsorption
Abstract: PTDC/FIS‐ AQM/31281/2017 PD/00193/2012 We report absolute photoabsorption cross sections for gas‐phase 2‐ and 5‐ bromopyrimidine in the 3.7–10.8 eV energy range, in a joint theoretical and experimental study. The measurements were carried out using high‐resolution vacuum ultraviolet synchrotron radiation, with quantum chemical calculations performed through the nuclear ensemble approach in combination with time‐dependent density functional theory, along with additional Franck–Condon Herzberg–Teller calculations for the first absorption band (3.7–4.6 eV). The cross sections of both bromopyrimidines are very similar below 7.3 eV, deviating more substantially from each other at higher energies. In the 7.3–9.0 eV range where the maximum cross‐section is found, a single and broad band is observed for 5‐bromopyrimidine, while more discernible features appear in the case of 2‐bromopyrimidine. Several π* ← π transitions account for the most intense bands, while weaker ones are assigned to transitions involving the nitrogen and bromine lone pairs, the antibonding σ*Br orbital, and the lower‐lying Rydberg states. A detailed comparison with the available photo‐absorption data of bromobenzene is also reported. We have found significant differences regarding the main absorption band, which is more peaked in bromobenzene, becoming broader and shifting to higher energies in both bromopyrimidines. In addition, there is a significant suppression of vibrational structures and of Rydberg states in the pair of isomers, most noticeably for 2‐bromopyrimidine. publishersversion published
Published: 2021
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5. Roadmap on dynamics of molecules and clusters in the gas phase

Author: Claire Romanzin, Alicja Domaracka, S. D. Tošić, Michael Gatchell, Jaroslav Kočišek, Simon Albertini, Mattea Carmen Castrovilli, Steen Brøndsted Nielsen, Ewa Erdmann, Janina Kopyra, Sylvain Maclot, Daniela Ascenzi, Amanda L. Steber, Klavs Hansen, Marta Łabuda, Christophe Jouvet, Lars H. Andersen, Dariusz G. Piekarski, Manuel Alcamí, Alicia Palacios, Sergio Díaz-Tendero, Henrik Cederquist, Elisabeth Gruber, Lorenzo Avaldi, Paola Bolognesi, Per Johnsson, Yoni Toker, Shirin Faraji, Oded Heber, Annemieke Petrignani, Christina Kjær, A. Candian, Aleksandar R. Milosavljević, Jennifer A. Noble, Paulo Limão-Vieira, Patrick Rousseau, Henning T. Schmidt, Eduardo Carrascosa, Juraj Fedor, Denis S. Tikhonov, Thomas Schlathölter, James N. Bull, Sadia Bari, Henning Zettergren, Department of Physics [Stockholm], Stockholm University, Centre de recherche sur les Ions, les MAtériaux et la Photonique (CIMAP - UMR 6252), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Zernike Institute for Advanced Materials, University of Groningen [Groningen], Istituto di Struttura della Materia (CNR-ISM), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Departamento de Química, Módulo 13, Universidad Autónoma de Madrid, 28049 Madrid (Spain), Department of Theoretical Physics and Quantum Information (DTPQI), ‎ Gdansk University of technology, Institute of Physics [Belgrade], University of Belgrade [Belgrade], Department of Physics (Göthenburg), University of Gothenburg (GU), Department of Physics, Mathematical Physics [Lund], Lund University [Lund], Deutsches Elektronen-Synchrotron [Hamburg] (DESY), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), Departamento de Química, Modulo 13, Universidad Autónoma de Madrid, Universidad Autónoma de Madrid (UAM), Institute of Physical Chemistry [Warsaw], Polish Academy of Sciences, Department III, Normandie Université (NU), Department of Physics (DPUT), University of Trento [Trento], Institut de Chimie Physique (ICP), Institut de Chimie du CNRS (INC)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Siedlce University of Natural Sciences and Humanities, Centro de Física e Investigação Tecnológica [Lisboa] (CEFITEC), Departamento de Fìsica [Lisboa] (DF), Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA), J. Heyrovský Institute of Physical Chemistry of the ASCR, Czech Academy of Sciences [Prague] (CAS), Institut für Ionenphysik und Angewandte Physik - Institute for Ion Physics and Applied Physics [Innsbruck], Leopold Franzens Universität Innsbruck - University of Innsbruck, Department of Physics and Astronomy [Aarhus], Aarhus University [Aarhus], Department of Particle Physics, Weizmann Institute of Science, Ajo, Bar-Ilan University [Israël], Tianjin University of Science and Technology (TUST), Physique des interactions ioniques et moléculaires (PIIM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Ecole Polytechnique Fédérale de Lausanne (EPFL), University of East Anglia [Norwich] (UEA), van ‘t Hoff Institute for Molecular Sciences, Universiteit van Amsterdam (UvA), DF – Departamento de Física, CeFITec – Centro de Física e Investigação Tecnológica, UAM. Departamento de Química, Molecular Processes Modeling Group, Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Caen Normandie (UNICAEN), Consiglio Nazionale delle Ricerche [Roma] (CNR), Universidad Autonoma de Madrid (UAM), School of Chemistry, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, United Kingdom, Van't Hoff Institute for Molecular Sciences, University of Amsterdam [Amsterdam] (UvA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU), Quantum interactions and structural dynamics, and Theoretical Chemistry
Subjects: ab-initio, Astrochemistry, cold ion spectroscopy, COLD ION SPECTROSCOPY, storage-ring, Clusters in the Gas Phase, Nanotechnology, 02 engineering and technology, Physics, Atomic, Molecular & Chemical, 010402 general chemistry, 01 natural sciences, Gas phase, POLYCYCLIC AROMATIC-HYDROCARBONS, resolved photoelectron-spectroscopy, fragmentation dynamics, Molecule, ddc:530, STORAGE-RING, THERMIONIC EMISSION, AB-INITIO, Physics, polycyclic aromatic-hydrocarbons, Science & Technology, low-energy electrons, LOW-ENERGY ELECTRONS, FRAGMENTATION DYNAMICS, RESOLVED PHOTOELECTRON-SPECTROSCOPY, [PHYS.PHYS.PHYS-ATM-PH]Physics [physics]/Physics [physics]/Atomic and Molecular Clusters [physics.atm-clus], Optics, SUPERFLUID-HELIUM DROPLETS, MASS-SPECTROMETRY, Química, mass-spectrometry, 021001 nanoscience & nanotechnology, Atomic and Molecular Physics, and Optics, 0104 chemical sciences, Dynamics of Molecules, superfluid-helium droplets, Physical Sciences, thermionic emission, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], 0210 nano-technology
Abstract: The European physical journal / D 75(5), 152 (2021). doi:10.1140/epjd/s10053-021-00155-y, This roadmap article highlights recent advances, challenges and future prospects in studies of the dynamics of molecules and clusters in the gas phase. It comprises nineteen contributions by scientists with leading expertise in complementary experimental and theoretical techniques to probe the dynamics on timescales spanning twenty order of magnitudes, from attoseconds to minutes and beyond, and for systems ranging in complexity from the smallest (diatomic) molecules to clusters and nanoparticles. Combining some of these techniques opens up new avenues to unravel hitherto unexplored reaction pathways and mechanisms, and to establish their significance in, e.g. radiotherapy and radiation damage on the nanoscale, astrophysics, astrochemistry and atmospheric science., Published by Springer, Heidelberg
Published: 2021
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6. On the electronic structure of methyl butyrate and methyl valerate

Author: Małgorzata A. Śmiałek, Denis Duflot, Søren Vrønning Hoffmann, Lucia Zuin, Nykola C. Jones, M A MacDonald, Nigel J. Mason, Paulo Limão-Vieira, DF – Departamento de Física, CeFITec – Centro de Física e Investigação Tecnológica, Department of Control and Power Engineering, Faculty of Ocean Engineering and Ship Technology, Gdańsk University of Technology (GUT)-Gdańsk University of Technology (GUT), Physico-Chimie Moléculaire Théorique (PCMT), Laboratoire de Physique des Lasers, Atomes et Molécules - UMR 8523 (PhLAM), Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Department of Physics and Astronomy [Aarhus], Aarhus University [Aarhus], Centre for Storage Ring Facilities [Aarhus] (ISA), Canadian Light Source Inc., University of Saskatchewan [Saskatoon] (U of S), School of Physical Sciences, University of Kent, Centro de Física e Investigação Tecnológica [Lisboa] (CEFITEC), Departamento de Fìsica [Lisboa] (DF), Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA), CPER CLIMIBIO, HPC resources from GENCI-TGCC (grant No. 2019-A0010806820), Centre deRessources Informatiques (CRI) of the Universit é de Lille, ANR-11-LABX-0005,Cappa,Physiques et Chimie de l'Environnement Atmosphérique(2011), and ANR-16-IDEX-0004,ULNE,ULNE(2016)
Subjects: chemistry.chemical_classification, 010304 chemical physics, Chemistry, Electronic structure, 010402 general chemistry, Photochemistry, Valerate, 01 natural sciences, Atomic and Molecular Physics, and Optics, 0104 chemical sciences, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, chemistry.chemical_compound, Ab initio quantum chemistry methods, Ionization, 0103 physical sciences, Methyl butyrate, Hydroxyl radical, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Ionization energy, HOMO/LUMO
Abstract: No. 2019-A0010806820 UIDB/00068/2020 PTDC/FIS-AQM/31281/2017 Abstract: We present novel results of the analysis of the electronic structure of two aliphatic esters: methyl butyrate and methyl valerate. High-resolution photoabsorption spectra were collected and analyzed over the energy range 4.0–10.8 eV and showed for both the molecules not only a clear band of the HOMO to LUMO transition, but also vibronic structure associated with the first Rydberg-valence transition. Photoelectron spectra recorded from 9 to over 28 eV revealed many ionization states with the first adiabatic ionization energies found to be 9.977 eV and 9.959 eV for methyl butyrate and methyl valerate, respectively. Ab initio calculations have been performed in order to help assign the photoabsorption and photoelectron features. Photolysis life times in the atmosphere were calculated revealing that photolysis is not competitive over hydroxyl radical scavenging in the process of removal of these esters from the atmosphere. Graphical abstract: [Figure not available: see fulltext.] publishersversion published
Published: 2020
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7. The electronic excited states of dichloromethane in the 5.8-10.8 eV energy range investigated by experimental and theoretical methods

Author: Małgorzata A. Śmiałek, Nykola C. Jones, Denis Duflot, Michael J. Brunger, Søren Vrønning Hoffmann, A. I. Lozano, Sarvesh Kumar, E. Lange, Paulo Limão-Vieira, M.G.P. Homem, Centro de Física e Investigação Tecnológica [Lisboa] (CEFITEC), Departamento de Fìsica [Lisboa] (DF), Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA), Centre for Storage Ring Facilities [Aarhus] (ISA), Aarhus University [Aarhus], Departamento de Química, Universidade Federal de São Carlos, Department of Control and Power Engineering, Faculty of Ocean Engineering and Ship Technology, Gdańsk University of Technology (GUT)-Gdańsk University of Technology (GUT), Physico-Chimie Moléculaire Théorique (PCMT), Laboratoire de Physique des Lasers, Atomes et Molécules - UMR 8523 (PhLAM), Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), College of Science and Engineering, Flinders University [Adelaide, Australia], Department of Actuarial Science and Applied Statistics, Faculty of Business and Information Science, UCSI University-UCSI University, Universidade Federal de São Carlos [São Carlos] (UFSCar), and ANR-16-IDEX-0004,ULNE,ULNE(2016)
Subjects: Physics, Radiation, Valence (chemistry), 010504 meteorology & atmospheric sciences, Photodissociation, 01 natural sciences, 7. Clean energy, Potential energy, Atomic and Molecular Physics, and Optics, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, symbols.namesake, Coupled cluster, Excited state, Scissoring, Rydberg formula, symbols, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Atomic physics, Spectroscopy, Excitation, 0105 earth and related environmental sciences
Abstract: International audience; We present a comprehensive experimental high-resolution vacuum ultraviolet (VUV) photoabsorption spectrum of dichloromethane, CH2Cl2, with absolute cross sections determined for the full 5.8–10.8 eV energy-range. The calculations on the vertical excitation energies and oscillator strengths were performed using the equation-of-motion coupled cluster method, restricted to the single and double excitations level (EOM-CCSD), and were used to help analyse the valence and Rydberg structures in the photoabsorption spectrum. The present spectrum additionally reveals several new features not previously reported in the literature, with particular reference to the valence σ*CCl (10a1) ← nCl (7b2) (11B2 ← X1A1) and (σ*CCl (10a1) ← nCl (9a1) + σ*CH (11a1) ← nCl (7b2)) (11A1 ← X 1A1) transitions at 7.519 and 7.793 eV. A vibrational progression of the CCl2 symmetric stretching, ν'3, and CCl2 scissoring, ν'4 (a1), modes have also been assigned for the first time in the 7.4–8.6 eV energy range. The measured absolute photoabsorption cross sections have been used to calculate the photolysis lifetime of dichloromethane in the Earth's atmosphere (0–50 km). Potential energy curves as a function of the C–Cl coordinate, for the four lowest-lying excited A′ and A″ electronic states, have additionally been calculated at the EOM-CCSD level of theory.
Published: 2020
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8. Ce:Nd:YAG continuous-wave solar-pumped laser

Author: Dawei Liang, Emmanuel Guillot, Dário Garcia, Cláudia R. Vistas, Bruno D. Tibúrcio, Joana Almeida, Centro de Física e Investigação Tecnológica [Lisboa] (CEFITEC), Departamento de Fìsica [Lisboa] (DF), Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA), Procédés, Matériaux et Energie Solaire (PROMES), Université de Perpignan Via Domitia (UPVD)-Centre National de la Recherche Scientifique (CNRS), and European Project: 823802,SFERA-III
Subjects: [PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics], Materials science, business.industry, Parabolic reflector, 02 engineering and technology, Solar-pumped laser, Radiation, 021001 nanoscience & nanotechnology, Laser, 01 natural sciences, Atomic and Molecular Physics, and Optics, Power level, Electronic, Optical and Magnetic Materials, law.invention, 010309 optics, Lens (optics), Focal zone, Optics, law, 0103 physical sciences, Continuous wave, Electrical and Electronic Engineering, 0210 nano-technology, business
Abstract: International audience; The proliferation of photovoltaic (PV) power generation in power distribution grids induces increasing safety and service quality concerns for grid operators. The inherent variability, essentially due to meteorological conditions, of PV power generation affects the power grid reliability. In order to develop efficient monitoring and control schemes for distribution grids, reliable forecasting of the solar resource at several time horizons that are related to regulation, scheduling, dispatching, and unit commitment, is necessary. PV power generation forecasting can result from forecasting global horizontal irradiance (GHI), which is the total amount of shortwave radiation received from above by a surface horizontal to the ground. A comparative study of machine learning methods is given in this paper, with a focus on the most widely used: Gaussian process regression (GPR), support vector regression (SVR), and artificial neural networks (ANN). Two years of GHI data with a time step of 10 min are used to train the models and forecast GHI at varying time horizons, ranging from 10 min to 4 h. Persistence on the clear-sky index, also known as scaled persistence model, is included in this paper as a reference model. Three criteria are used for in-depth performance estimation: normalized root mean square error (nRMSE), dynamic mean absolute error (DMAE) and coverage width-based criterion (CWC). Results confirm that machine learning-based methods outperform the scaled persistence model. The best-performing machine learning-based methods included in this comparative study are the long short-term memory (LSTM) neural network and the GPR model using a rational quadratic kernel with automatic relevance determination.
Published: 2020
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9. Simultaneous solar laser emissions from three Nd:YAG rods within a single pump cavity

Author: Joana Almeida, Cláudia R. Vistas, Bruno D. Tibúrcio, Dawei Liang, Emmanuel Guillot, Dário Garcia, Centro de Física e Investigação Tecnológica [Lisboa] (CEFITEC), Departamento de Fìsica [Lisboa] (DF), Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA), Procédés, Matériaux et Energie Solaire (PROMES), Université de Perpignan Via Domitia (UPVD)-Centre National de la Recherche Scientifique (CNRS), European Project: 823802,SFERA-III, CeFITec – Centro de Física e Investigação Tecnológica, and DF – Departamento de Física
Subjects: Materials science, 020209 energy, Physics::Optics, Multi-rod, 02 engineering and technology, Laser emission, Rod, law.invention, Optics, Materials Science(all), law, 0202 electrical engineering, electronic engineering, information engineering, Figure of merit, General Materials Science, SDG 7 - Affordable and Clean Energy, Laser power scaling, [PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics], Renewable Energy, Sustainability and the Environment, business.industry, Parabolic reflector, Parabolic mirror, YAG [Slope efficiency, Nd], Slope efficiency, 021001 nanoscience & nanotechnology, Laser, Lens (optics), Physics::Accelerator Physics, Solar-pumped laser, 0210 nano-technology, business, Beam (structure)
Abstract: FCT-MCTES grants SFRH/BPD/125116/2016, PD/BD/142827/2018, PD/BD/128267/2016 of C. R.Vistas, D. Garcia, B. D. Tiburcio, respectively, and FCT-MCTES Junior Researcher Contract CEECIND/03081/2017 of J. Almeida are acknowledged. We report here, to the best of our knowledge, the first simultaneous emission of three continuous-wave solar laser beams by end-side-pumping three 3.0 mm diameter, 25 mm length Nd:YAG single-crystal rods within a single conical pump cavity. An aspheric fused silica lens was used to couple the concentrated solar radiation from the focal zone of a parabolic mirror with 1.0 m2 effective collection area into the laser rods within the pump cavity. 18.3 W multimode solar laser power was measured, resulting in 5.1% laser slope efficiency. 0.036 W laser beam brightness figure of merit was also achieved for each beam, being 9 times more than that of the most efficient solar laser with 32.5 W/m2 collection efficiency. Since the three laser rods were associated with their own 1064 nm output mirrors, it was possible to adjust individually both solar laser output power levels and beam qualities of the three laser beams by adopting different resonant cavity lengths, enabling potential solar laser applications. authorsversion published
Published: 2020
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10. Stable solar-pumped TEM00-mode 1064 nm laser emission by a monolithic fused silica twisted light guide

Author: Said Mehellou, F. Rehouma, Rochdi Bouadjemine, Joana Almeida, Emmanuel Guillot, Cláudia R. Vistas, Dawei Liang, Centro de Física e Investigação Tecnológica [Lisboa] (CEFITEC), Departamento de Fìsica [Lisboa] (DF), Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA), Procédés, Matériaux et Energie Solaire (PROMES), Université de Perpignan Via Domitia (UPVD)-Centre National de la Recherche Scientifique (CNRS), and European Project: 312643,EC:FP7:INFRA,FP7-INFRASTRUCTURES-2012-1,SFERA-II(2014)
Subjects: Coupling, [PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics], Total internal reflection, Materials science, Renewable Energy, Sustainability and the Environment, business.industry, Mode (statistics), 02 engineering and technology, Solar-pumped laser, 021001 nanoscience & nanotechnology, Laser, 01 natural sciences, law.invention, 010309 optics, Optics, law, Optical cavity, 0103 physical sciences, Optoelectronics, General Materials Science, Laser power scaling, 0210 nano-technology, business, Nonimaging optics
Abstract: To improve TEM 00 -mode solar-pumped laser output power stability, a monolithic fused silica twisted light guide was firstly produced and then combined with both a 2D-CPC (Compound Parabolic Concentrator) and a 2 V-shaped cavity to achieve uniform pumping along a 3 mm diameter, 50 mm length, 1.0 at.% Nd 3+ :YAG rod through an heliostat-parabolic mirror system. Based on both refractive and total internal reflection principles, the light guide provided an effective solution to both guiding and redistributing highly concentrated solar radiations. A near-Gaussian profile focal spot was transformed into a uniform rectangular-shaped light column, facilitating further pump light coupling into the long and thin laser rod within the 2 V-shaped pump cavity. Optimum pumping parameters and solar laser output powers were found through both ZEMAX© non-sequential ray-tracing and LASCAD© laser cavity analysis codes. The light guide reduced considerably the thermal lensing effects of the solar laser. 2.7 W continuous-wave TEM 00 -mode (M 2 ≤ 1.05) 1064 nm solar laser emission with 2.3 W/m 2 collection efficiency and, more importantly, with 1.7% stability was finally achieved, being significantly more stable than the previous TEM 00 -mode solar lasers.
Published: 2017
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11. Combined Experimental and Theoretical Studies on Electron Transfer in Potassium Collisions with CCl4

Author: T. Cunha, A. I. Lozano, G. García, Paulo Limão-Vieira, Sarvesh Kumar, Pedro Pereira, M. Mendes, Marie-Christine Bacchus-Montabonel, Khrystyna Regeta, Augusto M.C. Moutinho, Swiss National Science Foundation, Fundação para a Ciência e a Tecnologia (Portugal), Ministerio de Economía y Competitividad (España), Consejo Superior de Investigaciones Científicas (España), Centro de Física e Investigação Tecnológica [Lisboa] (CEFITEC), Departamento de Fìsica [Lisboa] (DF), Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA), Instituto Superior de Engenharia de Lisboa (ISEL), Instituto de Física Fundamental [Madrid] (IFF), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Physico-chimie théorique (THEOCHEM), Institut Lumière Matière [Villeurbanne] (ILM), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)
Subjects: CCl4, Anions, Potassium, Electrical energy, chemistry.chemical_element, 010402 general chemistry, digestive system, 01 natural sciences, Ion, Electron transfer, [SPI]Engineering Sciences [physics], 0103 physical sciences, Atom, Molecule, [CHIM]Chemical Sciences, Collisions, Physical and Theoretical Chemistry, [PHYS]Physics [physics], Potassium collisions, Energy, 010304 chemical physics, Chemistry, 0104 chemical sciences, 3. Good health, Atomic physics
Abstract: 8 pags., 5 figs., Negative ion formation in electron transfer experiments from fast neutral potassium (K) atom collisions with neutral tetrachloromethane (CCl) molecules has been investigated in the laboratory frame range of 8-1000 eV. Comprehensive calculations on the electronic structure were performed for CCl in the presence of a potassium atom and used to help analyze the lowest unoccupied molecular orbitals participating in the collision process. Additionally, K energy loss produced in the forward direction has served to further our knowledge on the electronic state spectroscopy of CCl. A vertical electron affinity of -0.79 ± 0.20 eV has been obtained and assigned to a purely repulsive transition from CCl ground state to the T state of the temporary negative ion yielding Cl formation. Other features in the energy loss spectrum were observed for the first time and related to Cl , CCl , and CCl formation. Special attention is also given to the unresolved feature corresponding to a positive electron affinity of 0.24 ± 0.2 eV, assigned to a vibrationally hot transition from CCl ground state into the triply degenerate T excited state of the negative ion. The combined time-of-flight mass spectrometry together with K energy loss data represents the most comprehensive assignment of the tetrachloromethane anion yields and the role of CCl electronic states in collision induced dissociation to date., K.R. acknowledges the Swiss National Science Foundation for EPM fellowship. S.K., T.C., and M.M. acknowledge the Portuguese National Funding Agency (FCT) through Grants PD/BD/142831/2018, SFRH/BD/52538/2014, and PD/BD/ 106038/2015, and together with A.I.L., P.J.S.P. and P.L.-V. the Research Grants CEFITEC (UIDB/00068/2020) and PTDC/ FIS-AQM/31281/2017. This work was also supported by the Radiation Biology and Biophysics Doctoral Training Programme (RaBBiT; Grant PD/00193/2012) and UCIBIO (Grant UIDB/04378/2020). G.G. acknowledges partial financial support from the Spanish Ministerio de Ciencia, Innovacion y Universidades (Project No. FIS2016-80440) and ́ CSIC (Project LINKA20085). M.C.B.-M. acknowledges support from the computational resources from the CCIN2P3 in Villeurbanne and CCRT/CINES/IDRIS by GENCI (Grand Equipement National de Calcul Intensif) under Allocation A0030807662.
Published: 2020
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12. Low-energy electron interaction with nitroimidazole-based radiosensitisers under isolated and hydrated conditions

Author: Meißner, R., Lochmann, C., Feketeová, L., Kocisek, J., Fedor, J., Fárník, M., Limão-Vieira, Paulo, Denifl, S., Institut de Physique Nucléaire de Lyon (IPNL), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Centro de Física e Investigação Tecnológica [Lisboa] (CEFITEC), Departamento de Fìsica [Lisboa] (DF), Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA), Institut für Ionenphysik und Angewandte Physik - Institute for Ion Physics and Applied Physics [Innsbruck], and Leopold Franzens Universität Innsbruck - University of Innsbruck
Subjects: [PHYS.PHYS.PHYS-ATM-PH]Physics [physics]/Physics [physics]/Atomic and Molecular Clusters [physics.atm-clus], ComputingMilieux_MISCELLANEOUS
Abstract: International audience
Published: 2019

13. Ion-Pair Formation in Neutral Potassium-Neutral Pyrimidine Collisions: Electron Transfer Experiments

Author: Gustavo García, Paulo Limão-Vieira, Antonio Aguilar, F. Ferreira da Silva, Sarvesh Kumar, M. Mendes, Beatriz Pamplona, Marie-Christine Bacchus-Montabonel, Fundação para a Ciência e a Tecnologia (Portugal), Ministerio de Economía y Competitividad (España), SCOAP, Centro de Física e Investigação Tecnológica [Lisboa] (CEFITEC), Departamento de Fìsica [Lisboa] (DF), Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA), Instituto de Física Fundamental [Madrid] (IFF), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Universitat de Barcelona (UB), Physico-chimie théorique (THEOCHEM), Institut Lumière Matière [Villeurbanne] (ILM), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)
Subjects: pyrimidine, energy loss, negative ions, 02 engineering and technology, Electron, 010402 general chemistry, Potassium Cation, time-of-flight, 01 natural sciences, Ion, lcsh:Chemistry, Electron transfer, Fragmentation (mass spectrometry), calculations, Molecule, Molecular orbital, Ions, Chemistry, General Chemistry, Pirimidines, 021001 nanoscience & nanotechnology, Alkali metal, 0104 chemical sciences, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Crystallography, Pyrimidines, lcsh:QD1-999, 0210 nano-technology, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract: 10 pags., 5 figs., 1 tab. -- Open Access funded by Creative Commons Atribution Licence 4.0, We report novel data on ion-pair formation in hyperthermal (30–800 eV) neutral potassium collisions with neutral pyrimidine (Pyr, C4H4N2) molecules. In this collision regime, negative ions formed by electron transfer from the alkali atom to the target molecule were time-of-flight mass analyzed and the fragmentation patterns and branching ratios have been obtained. The most abundant product anions have been assigned to CN− and C2H− and the electron transfer mechanisms are comprehensively discussed. Particular importance is also given to the efficient loss of integrity of the pyrimidine ring in the presence of an extra electron, which is in contrast to dissociative electron attachment experiments yielding the dehydrogenated parent anion. Theoretical calculations were performed for pyrimidine in the presence of a potassium atom and provided a strong basis for the assignment of the lowest unoccupied molecular orbitals accessed in the collision process. In order to further our knowledge about the collision dynamics, potassium cation (K+) energy loss spectrum has been obtained and within this context, we also discuss the role of the accessible electronic states. A vertical electron affinity of (−5.69 ± 0.20) eV was obtained and may be assigned to a π3*(b1) state that leads to CN− formation., MM, SK, and FdS acknowledge the Portuguese National Funding Agency FCT-MCTES through PD/BD/106038/2015, PD/BD/142831/2018, and researcher position IF-FCT IF/00380/2014, respectively, and together with PL-V the Research Grants UID/FIS/00068/2019 (CEFITEC), PTDC/FISAQM/31215/2017, and PTDC/FIS-AQM/31281/2017. This work was also supported by Radiation Biology and Biophysics Doctoral Training Programme (RaBBiT, PD/00193/2012); UID/Multi/04378/2013 (UCIBIO). GG and AA acknowledge partial financial support from the Spanish Ministerio de Economia, Industria y Competitividad, Project No. FIS2016- 80440 and Project CTQ2013-41307-P. M-CB-M acknowledges support from the computational resources from the CCIN2P3 in Villeurbanne and CCRT/CINES/IDRIS by GENCI (Grand Equipement National de Calcul Intensif) under the allocation A0030807662.
Published: 2019
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14. Solar-pumped Nd:YAG laser with 31.5 W/m2 multimode and 7.9 W/m2 TEM00-mode collection efficiencies

Author: Emmanuel Guillot, Joana Almeida, Dawei Liang, Cláudia R. Vistas, Centro de Física e Investigação Tecnológica [Lisboa] (CEFITEC), Departamento de Fìsica [Lisboa] (DF), Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA), Procédés, Matériaux et Energie Solaire (PROMES), Université de Perpignan Via Domitia (UPVD)-Centre National de la Recherche Scientifique (CNRS), and European Project: 312643,EC:FP7:INFRA,FP7-INFRASTRUCTURES-2012-1,SFERA-II(2014)
Subjects: 010302 applied physics, [PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics], Multi-mode optical fiber, Materials science, Renewable Energy, Sustainability and the Environment, business.industry, Parabolic reflector, Slope efficiency, Physics::Optics, Solar energy, Laser, 01 natural sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, law.invention, 010309 optics, Lens (optics), Optics, law, Nd:YAG laser, 0103 physical sciences, Optoelectronics, Astrophysics::Earth and Planetary Astrophysics, Laser power scaling, business
Abstract: We report here significant progresses in both multimode and TEM00-mode solar-pumped laser collection efficiencies by end-side-pumping a 4.0 mm diameter 35 mm length Nd: YAG single-crystal rod with a heliostat-parabolic mirror solar energy concentration system. An aspheric fused silica lens was used to couple the concentrated solar radiations from the focal zone of a 1.4 m effective diameter parabolic mirror into the laser rod within a conical pumping cavity. 37.2 W continuous-wave multimode solar laser power was measured, corresponding to 31.5 W/m2 multimode laser collection efficiency and 8.9% slope efficiency. 9.3 W continuous-wave TEM00-mode (M2 ≤1.2) solar laser power and consequently 7.9 W/m2 fundamental-mode laser collection efficiency was registered, doubling the previous record.
Published: 2017
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15. TEM00 mode Nd:YAG solar laser by side-pumping a grooved rod

Author: Emmanuel Guillot, Dawei Liang, Joana Almeida, Cláudia R. Vistas, Centro de Física e Investigação Tecnológica [Lisboa] (CEFITEC), Departamento de Fìsica [Lisboa] (DF), Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA), Procédés, Matériaux et Energie Solaire (PROMES), and Université de Perpignan Via Domitia (UPVD)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Materials science, Resonator, chemistry.chemical_element, 02 engineering and technology, Single-mode laser, 7. Clean energy, 01 natural sciences, Neodymium, law.invention, 010309 optics, [SPI]Engineering Sciences [physics], Optics, law, 0103 physical sciences, Laser power scaling, Electrical and Electronic Engineering, Physical and Theoretical Chemistry, Parabolic reflector, business.industry, Parabolic mirror, Slope efficiency, Solar-pumped laser, 021001 nanoscience & nanotechnology, Laser, Atomic and Molecular Physics, and Optics, Electronic, Optical and Magnetic Materials, Lens (optics), chemistry, [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, Optoelectronics, 0210 nano-technology, business, Solar heliostat
Abstract: International audience; A simple TEM00 mode solar laser system with a grooved Nd:YAG rod pumped through a heliostat-parabolic mirror system is reported here. The radiation coupling capacity of a fused silica tube lens was combined with the multipass pumping ability of a 2 V-shaped cavity to provide efficient side-pumping along a 4.0 mm diameter grooved Nd:YAG single-crystal rod. TEM00 mode solar laser power of 3.4 W was measured by adopting an asymmetric large-mode laser resonant cavity. Record TEM00 mode solar laser collection efficiency of 3.4 W/m2and slope efficiency of 1.9% was achieved, which corresponds to 1.8 and 2.4 times more than the previous TEM00 mode Nd:YAG solar laser using the PROMES-CNRS heliostat-parabolic mirror system, respectively.
Published: 2016
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16. Electron transfer induced decomposition in potassium–nitroimidazoles collisions: an experimental and theoretical work

Author: Paulo Limão-Vieira, Marie-Christine Bacchus-Montabonel, M. Mendes, Gustavo García, Fundação para a Ciência e a Tecnologia (Portugal), Ministerio de Economía y Competitividad (España), DF – Departamento de Física, CeFITec – Centro de Física e Investigação Tecnológica, Centro de Física e Investigação Tecnológica [Lisboa] (CEFITEC), Departamento de Fìsica [Lisboa] (DF), Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA), Instituto de Física Fundamental [Madrid] (IFF), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Physico-chimie théorique (THEOCHEM), Institut Lumière Matière [Villeurbanne] (ILM), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)
Subjects: Potassium, Ab initio, chemistry.chemical_element, negative ions, time-of-flight (TOF) mass spectrometry, 010402 general chemistry, 01 natural sciences, Article, Mass Spectrometry, Catalysis, Ion, Inorganic Chemistry, [SPI]Engineering Sciences [physics], Electron transfer, Fragmentation (mass spectrometry), 0103 physical sciences, Atom, [CHIM]Chemical Sciences, Molecule, Molecular orbital, Physical and Theoretical Chemistry, Molecular Biology, Spectroscopy, [PHYS]Physics [physics], nitroimidazoles, 010304 chemical physics, Chemistry, Organic Chemistry, General Medicine, electron transfer, fragmentation pattern, 0104 chemical sciences, Computer Science Applications, Physical chemistry
Abstract: Electron transfer induced decomposition mechanism of nitroimidazole and a selection of analogue molecules in collisions with neutral potassium (K) atoms from 10 to 1000 eV have been thoroughly investigated. In this laboratory collision regime, the formation of negative ions was time-of-flight mass analyzed and the fragmentation patterns and branching ratios have been obtained. The most abundant anions have been assigned to the parent molecule and the nitrogen oxide anion (NO2–) and the electron transfer mechanisms are comprehensively discussed. This work focuses on the analysis of all fragment anions produced and it is complementary of our recent work on selective hydrogen loss from the transient negative ions produced in these collisions. Ab initio theoretical calculations were performed for 4-nitroimidazole (4NI), 2-nitroimidazole (2NI), 1-methyl-4- (Me4NI) and 1-methyl-5-nitroimidazole (Me5NI), and imidazole (IMI) in the presence of a potassium atom and provided a strong basis for the assignment of the lowest unoccupied molecular orbitals accessed in the collision process., This research was funded by the Portuguese National Funding Agency FCT-MCTES through PD/BD/106038/2015 and research grants UID/FIS/00068/2019 (CEFITEC) and PTDC/FIS-AQM/31281/2017. This work was also supported by the Radiation Biology and Biophysics Doctoral Training Programme (RaBBiT, PD/00193/2012) and UID/Multi/04378/2013 (UCIBIO). G.G. was partially funded by the Spanish Ministerio de Ciencia, Innovación y Universidades (project no. FIS2016-80440) and CSIC(project no. LINKA20085).
Published: 2019
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17. Low-energy electron scattering from radiosensitizers: Associative vs. dissociative attachment

Author: Denifl, Stephan, Meißner, R., Ameixa, J., Arthur-Baidoo, E., Lochmann, C., Feketeová, L., Illenberger, Eugen, Kocisek, J., Fedor, J., Ferreira da Silva, Filipe, Limao-Vieira, P., Makurat, S., Kozak, W., Rak, J., Institut für Ionenphysik und Angewandte Physik - Institute for Ion Physics and Applied Physics [Innsbruck], Leopold Franzens Universität Innsbruck - University of Innsbruck, Institut de Physique Nucléaire de Lyon (IPNL), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Centro de Física e Investigação Tecnológica [Lisboa] (CEFITEC), Departamento de Fìsica [Lisboa] (DF), Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), and Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)
Subjects: [PHYS.PHYS.PHYS-ATM-PH]Physics [physics]/Physics [physics]/Atomic and Molecular Clusters [physics.atm-clus], ComputingMilieux_MISCELLANEOUS
Abstract: International audience
Published: 2018

18. Dissociative electron attachment to nimorazole

Author: Meißner, R., Feketeová, L., Limão-Vieira, Paulo, Denifl, S., Institut de Physique Nucléaire de Lyon (IPNL), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Centro de Física e Investigação Tecnológica [Lisboa] (CEFITEC), Departamento de Fìsica [Lisboa] (DF), Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA), Institut für Ionenphysik und Angewandte Physik - Institute for Ion Physics and Applied Physics [Innsbruck], and Leopold Franzens Universität Innsbruck - University of Innsbruck
Subjects: [PHYS.PHYS.PHYS-ATM-PH]Physics [physics]/Physics [physics]/Atomic and Molecular Clusters [physics.atm-clus], ComputingMilieux_MISCELLANEOUS
Abstract: International audience
Published: 2018

19. Electron transfer driven decomposition of adenine and selected analogs as probed by experimental and theoretical methods

Author: M. Mendes, Gustavo García, Paulo Limão-Vieira, F. Ferreira da Silva, Samuel Eden, T. Cunha, Marie-Christine Bacchus-Montabonel, Hydrosystèmes et bioprocédés (UR HBAN), Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Centro de Física e Investigação Tecnológica [Lisboa] (CEFITEC), Departamento de Fìsica [Lisboa] (DF), Faculdade de Ciências e Tecnologia (FCT NOVA), Universidade Nova de Lisboa (NOVA)-Universidade Nova de Lisboa (NOVA)-Faculdade de Ciências e Tecnologia (FCT NOVA), Universidade Nova de Lisboa (NOVA)-Universidade Nova de Lisboa (NOVA), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), Institut Lumière Matière [Villeurbanne] (ILM), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), Dept. of Physics and Astronomy, The Open University [Milton Keynes] (OU), Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA), Instituto de Física Fundamental [Madrid] (IFF), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Fundação para a Ciência e a Tecnologia (Portugal), Ministerio de Economía y Competitividad (España), and Engineering and Physical Sciences Research Council (UK)
Subjects: Ab initio, General Physics and Astronomy, Collision energies, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, Dissociation (chemistry), Ion, Autoionization, Electron transfer, Chemical compounds, Fragmentation (mass spectrometry), Electrostatics, Molecular orbital, Physical and Theoretical Chemistry, ComputingMilieux_MISCELLANEOUS, Nucleobases, Cyanides, Mass spectrometry, Chemistry, 021001 nanoscience & nanotechnology, Lowest unoccupied molecular orbitals, 0104 chemical sciences, 3. Good health, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Crystallography, Intramolecular force, Chemical elements, Mass spectrum, Atomic and molecular collisions, 0210 nano-technology, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract: 9 pags., 6 figs., 1 tab., We report on a combined experimental and theoretical study of electron-transfer-induced decomposition of adenine (Ad) and a selection of analog molecules in collisions with potassium (K) atoms. Time-of-flight negative ion mass spectra have been obtained in a wide collision energy range (6-68 eV in the centre-of-mass frame), providing a comprehensive investigation of the fragmentation patterns of purine (Pu), adenine (Ad), 9-methyl adenine (9-mAd), 6-dimethyl adenine (6-dimAd), and 2-D adenine (2-DAd). Following our recent communication about selective hydrogen loss from the transient negative ions (TNIs) produced in these collisions [T. Cunha et al., J. Chem. Phys. 148, 021101 (2018)], this work focuses on the production of smaller fragment anions. In the low-energy part of the present range, several dissociation channels that are accessible in free electron attachment experiments are absent from the present mass spectra, notably NH loss from adenine and 9-methyl adenine. This can be understood in terms of a relatively long transit time of the K cation in the vicinity of the TNI tending to enhance the likelihood of intramolecular electron transfer. In this case, the excess energy can be redistributed through the available degrees of freedom inhibiting fragmentation pathways. Ab initio theoretical calculations were performed for 9-methyl adenine (9-mAd) and adenine (Ad) in the presence of a potassium atom and provided a strong basis for the assignment of the lowest unoccupied molecular orbitals accessed in the collision process., T.C., M.M., and F.F.d.S. acknowledge the Portuguese National Funding Agency FCT-MCTES through Nos. SFRH/BD/52538/2014, PD/BD/106038/2015, and researcher position IF-FCT IF/00380/2014, respectively, and together with PLV the research Grant No. UID/FIS/00068/2013. This work was also supported by Radiation Biology and Biophysics Doctoral Training Programme (RaBBiT, No. PD/00193/2010); No. UID/Multi/04378/2013 (UCIBIO). G.G. acknowledges partial financial support from the Spanish Ministerio de Economia, Industria y Competitividad (Project No. FIS2016-80440). S.E. acknowledges the support of the British EPSRC through a Career Acceleration Fellowship (No. EP/J002577/1) and a Research Grant (No. EP/L002191/1). M.-C.B.-M. acknowledges support from the computational resources from the CCIN2P3 in Villeurbanne and CCRT/CINES/IDRIS by GENCI (Grand Equipement National de Calcul Intensif) under the Allocation No. x2017087662
Published: 2018
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20. 5.5 W continuous-wave TEM00-mode Nd:YAG solar laser by a light-guide/2V-shaped pump cavity

Author: Cláudia R. Vistas, Emmanuel Guillot, R. Bouadjemine, Dawei Liang, Joana Almeida, Centro de Física e Investigação Tecnológica [Lisboa] (CEFITEC), Departamento de Fìsica [Lisboa] (DF), Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA), Procédés, Matériaux et Energie Solaire (PROMES), Université de Perpignan Via Domitia (UPVD)-Centre National de la Recherche Scientifique (CNRS), and European Project: 312643,EC:FP7:INFRA,FP7-INFRASTRUCTURES-2012-1,SFERA-II(2014)
Subjects: Quantum optics, [PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics], Materials science, Physics and Astronomy (miscellaneous), business.industry, Parabolic reflector, Slope efficiency, General Engineering, Physics::Optics, General Physics and Astronomy, Laser, law.invention, Resonator, Optics, law, Nd:YAG laser, Optoelectronics, Continuous wave, Laser power scaling, business
Abstract: A significant progress in TEM00-mode solar laser power and efficiency with heliostat–parabolic mirror system is reported here. A double-stage light-guide/2V-shaped pump cavity is used to efficiently couple and redistribute the concentrated pump light from a 2-m-diameter parabolic mirror to a 4-mm-diameter, 30-mm-length, 1.1 at.% Nd:YAG single-crystal rod. The light guide with large rectangular cross section enables a stable uniform pumping profile along the laser rod, resulting also in an enhanced tracking error compensation capacity. 5.5 W cw TEM00-mode solar laser power was measured at the output of a thermally near unstable asymmetric resonator. 150 and 157 % improvement in TEM00-mode solar laser collection efficiency and slope efficiency were obtained, respectively.
Published: 2015
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21. Comprehensive investigation of the electronic excitation of W(CO)6 by photoabsorption and theoretical analysis in the energy region from 3.9 to 10.8 eV

Author: Khrystyna Regeta, Nykola C. Jones, Chantal Daniel, M. Mendes, Gustavo García, Paulo Limão-Vieira, Søren Vrønning Hoffmann, F. Ferreira da Silva, Aarhus University Research Foundation, Université de Strasbourg, European Cooperation in Science and Technology, European Commission, Ministerio de Economía, Industria y Competitividad (España), Swiss National Science Foundation, Fundação para a Ciência e a Tecnologia (Portugal), Centro de Física e Investigação Tecnológica [Lisboa] (CEFITEC), Departamento de Fìsica [Lisboa] (DF), Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA), Department of Physics and Astronomy [Aarhus], Aarhus University [Aarhus], Institut de Chimie de Strasbourg, Université de Strasbourg (UNISTRA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), and Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)
Subjects: Photoabsorption, General Physics and Astronomy, lcsh:Chemical technology, lcsh:Technology, 7. Clean energy, 01 natural sciences, Dissociation (chemistry), CARBONYLS, DENSITY-FUNCTIONAL THEORY, ABSORPTION-SPECTROSCOPY, chemistry.chemical_compound, lcsh:TP1-1185, General Materials Science, Electron beam-induced deposition, lcsh:Science, ComputingMilieux_MISCELLANEOUS, density functional theory (DFT) calculations, AB-INITIO, 010304 chemical physics, Chemistry, Time-dependent density functional theory, lcsh:QC1-999, 3. Good health, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, photoabsorption, Excited state, Tungsten hexacarbonyl, VIBRATIONAL SPECTRA, COMPLEXES, Atomic physics, Focused electron beam induced deposition (FEBID), Electron scattering, Absorption spectroscopy, TRANSITION-METAL HEXACARBONYLS, 010402 general chemistry, TUNGSTEN HEXACARBONYL, 0103 physical sciences, Electrical and Electronic Engineering, lcsh:T, cross sections, TD-DFT ANALYSIS, Density functional theory (DFT) calculations, 0104 chemical sciences, Cross sections, EXCITED-STATES, focused electron beam induced deposition (FEBID), lcsh:Q, lcsh:Physics, Excitation
Abstract: High-resolution vacuum ultraviolet photoabsorption measurements in the wavelength range of 115-320 nm (10.8-3.9 eV) have been performed together with comprehensive relativistic time-dependent density functional calculations (TDDFT) on the low-lying excited sates of tungsten hexacarbonyl, W(CO). The higher resolution obtained reveals previously unresolved spectral features of W(CO). The spectrum shows two higher-energy bands (in the energy ranges of 7.22-8.12 eV and 8.15-9.05 eV), one of them with clear vibrational structure, and a few lower-energy shoulders in addition to a couple of lower-energy metal-to-ligand charge-transfer (MLCT) bands reported in the literature before. Absolute photoabsorption cross sections are reported and, where possible, compared to previously published results. On the basis of this combined experimental/theoretical study the absorption spectrum of the complex has been totally re-assigned between 3.9 and 10.8 eV under the light of spin-orbit coupling (SOC) effects. The present comprehensive knowledge of the nature of the electronically excited states may be of relevance to estimate neutral dissociation cross sections of W(CO), a precursor molecule in focused electron beam induced deposition (FEBID) processes, from electron scattering measurements., MM and FFS acknowledge the Portuguese National Funding Agency FCT-MCTES through grants PD/BD/106038/2015 and researcher position IF-FCT IF/00380/2014, respectively, and together with PLV the research grant UID/FIS/00068/2013. KR acknowledges the Swiss National Science Foundation for an Early Postdoc Mobility fellowship. This work was also supported by Radiation Biology and Biophysics Doctoral Training Programme (RaBBiT, PD/00193/2012); UID/Multi/ 04378/ 2013 (UCIBIO). GG acknowledges partial financial support from the Spanish Ministerio de Economia, Industria y Competitividad (Project No. FIS2016-80440). CD thanks The Labex “Chimie des Systèmes Complexes” (ANR-10-LABX- 0026_CSC). The quantum chemical calculations have been performed on the computer nodes of the LCQS, Strasbourg and thanks to the computer facilities of the High Performance Computing (HPC) regional center of University of Strasbourg. The authors wish to acknowledge the beam time at the ASTRID2 synchrotron at ISA, Aarhus University, Denmark. We also acknowledge the financial support provided by the European Community's Seventh Framework Programme (FP7/ 2007-2013) CALIPSO under grant agreement number 312284. Some of this work forms part of the EU/ESF COST Action CELINA CM1301, 11 pags., 4 figs., 2 tabs. -- This article is part of the Thematic Series "Chemistry for electron-induced nanofabrication".
Published: 2017
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22. Threshold behavior in metastable dissociation of multi-photon ionized thymine and uracil

Author: Jean-Christophe Poully, Rahul Pandey, M. Ryszka, Paulo Limão-Vieira, Samuel Eden, Mathieu Lalande, Marcin Dampc, Nigel J. Mason, T. da Fonseca Cunha, Department of Mines and Geology, National Seismological Center, OSA (XLIM-OSA), XLIM (XLIM), Université de Limoges (UNILIM)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Centre National de la Recherche Scientifique (CNRS), Centro de Física e Investigação Tecnológica [Lisboa] (CEFITEC), Departamento de Fìsica [Lisboa] (DF), Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA), Centre of Molecular and Optical Sciences [Milton Keynes] (CeMOS), Department of Physics and Astronomy [Milton Keynes], The Open University [Milton Keynes] (OU)-The Open University [Milton Keynes] (OU), Centre de recherche sur les Ions, les MAtériaux et la Photonique (CIMAP - UMR 6252), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Department of Physics and Astronomy [UCL London], University College of London [London] (UCL), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Caen Normandie (UNICAEN), and Normandie Université (NU)
Subjects: Pyrimidine, [PHYS.PHYS.PHYS-BIO-PH]Physics [physics]/Physics [physics]/Biological Physics [physics.bio-ph], General Physics and Astronomy, Photoionization, Photon energy, 010402 general chemistry, 01 natural sciences, Nucleobase, chemistry.chemical_compound, Computer Science::Systems and Control, [CHIM.ANAL]Chemical Sciences/Analytical chemistry, Metastability, 0103 physical sciences, Physical and Theoretical Chemistry, Astrophysics::Galaxy Astrophysics, ComputingMilieux_MISCELLANEOUS, Quantitative Biology::Biomolecules, 010304 chemical physics, [PHYS.PHYS.PHYS-ATM-PH]Physics [physics]/Physics [physics]/Atomic and Molecular Clusters [physics.atm-clus], Uracil, Threshold energy, Quantitative Biology::Genomics, 0104 chemical sciences, Thymine, chemistry, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Atomic physics, [CHIM.RADIO]Chemical Sciences/Radiochemistry
Abstract: Microsecond-timescale HNCO loss has been observed from single-color multi-photon ionized pyrimidine nucleobases in the gas phase. Photon energy thresholds for the metastable channels have been measured at 5.55 ± 0.02 eV for thymine and 5.57 ± 0.02 eV for uracil. We argue that these results can be attributed to accessing the molecules’ S1 states with additional vibrational energy matching the threshold energy for HNCO loss from the radical cation. Combined with previous photoionization energies, this enables the S1 adiabatic energies to be deduced: 3.67 ± 0.07 eV for thymine and 3.77 ± 0.07 eV for uracil. These values are consistent with recent calculations.
Published: 2017
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23. Cross sections for electron scattering from α-tetrahydrofurfuryl alcohol

Author: H. V. Duque, Michael J. Brunger, Z. Pettifer, Kuru Ratnavelu, M. C. A. Lopes, Darryl Jones, M.-J. Hubin-Franskin, Gustavo García, Luca Chiari, P. A. Thorn, Denis Duflot, Francisco J. Blanco, Jacques Delwiche, G. B. da Silva, Ronald D. White, Paulo Limão-Vieira, School of Chemical and Physical Sciences, Flinders Universiy, Departamento de Física, Universidade Federal de Juiz de Fora, Universidade Federal de Mato Grosso, Centro de Física e Investigação Tecnológica [Lisboa] (CEFITEC), Departamento de Fìsica [Lisboa] (DF), Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA), Physico-Chimie Moléculaire Théorique (PCMT), Laboratoire de Physique des Lasers, Atomes et Molécules - UMR 8523 (PhLAM), Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Spectroscopie d'Electrons Diffusés, Université de Liège, Departamento de Fisica Atomica, Molecular y Nuclear, Universidad Complutense de Madrid = Complutense University of Madrid [Madrid] (UCM), Instituto de Física Fundamental [Madrid] (IFF), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Institute of Mathematical Sciences, University of Malaya = Universiti Malaya [Kuala Lumpur, Malaisie] (UM), School of Engineering and Physical Sciences, James Cook University (JCU), ANR-11-LABX-0005,Cappa,Physiques et Chimie de l'Environnement Atmosphérique(2011), and University of Malaya
Subjects: Range (particle radiation), 010304 chemical physics, Chemistry, General Physics and Astronomy, 01 natural sciences, 7. Clean energy, Dissociation (psychology), Cross section (physics), symbols.namesake, Ionization, 0103 physical sciences, Rydberg formula, symbols, medicine, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Physical and Theoretical Chemistry, Atomic physics, medicine.symptom, 010306 general physics, Electron scattering, Excitation, Electron ionization
Abstract: International audience; We report on measurements of integral cross sections (ICSs) for electron impact excitation of a series of Rydberg electronic-states in α-tetrahydrofurfuryl alcohol. The energy range of these experiments was 20–50 eV. There are currently no other results against which we can directly compare those measured data. We also report results from our independent atom model with screened additivity rule correction computations, namely for the total cross section, elastic ICS, inelastic ICS (all discrete electronic states and neutral dissociation) and the total ionisation ICS. Where possible, our calculated cross sections are compared to the limited available data of each scattering process.
Published: 2014
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24. Stabilities of nanohydrated thymine radical cations: insights from multiphoton ionization experiments and ab initio calculations

Author: Samuel Eden, Rahul Pandey, Nigel J. Mason, Paulo Limão-Vieira, M. Ryszka, Jean-Christophe Poully, Mathieu Lalande, The Open University [Milton Keynes] (OU), Centre de recherche sur les Ions, les MAtériaux et la Photonique (CIMAP - UMR 6252), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Centro de Física e Investigação Tecnológica [Lisboa] (CEFITEC), Departamento de Fìsica [Lisboa] (DF), Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA), School of Physical Sciences [Milton Keynes], Faculty of Science, Technology, Engineering and Mathematics [Milton Keynes], The Open University [Milton Keynes] (OU)-The Open University [Milton Keynes] (OU), Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Caen Normandie (UNICAEN), Normandie Université (NU), and School of Physical Sciences, University of Kent
Subjects: [PHYS.PHYS.PHYS-BIO-PH]Physics [physics]/Physics [physics]/Biological Physics [physics.bio-ph], Binding energy, 010402 general chemistry, 01 natural sciences, Ab initio quantum chemistry methods, [CHIM.ANAL]Chemical Sciences/Analytical chemistry, Ionization, Metastability, 0103 physical sciences, Physics::Chemical Physics, Conformational isomerism, ComputingMilieux_MISCELLANEOUS, Astrophysics::Galaxy Astrophysics, Quantitative Biology::Biomolecules, 010304 chemical physics, Chemistry, Intermolecular force, [PHYS.PHYS.PHYS-ATM-PH]Physics [physics]/Physics [physics]/Atomic and Molecular Clusters [physics.atm-clus], Optical physics, Atomic and Molecular Physics, and Optics, 0104 chemical sciences, Solvation shell, Physical chemistry, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Astrophysics::Earth and Planetary Astrophysics, Atomic physics, [CHIM.RADIO]Chemical Sciences/Radiochemistry
Abstract: Multi-photon ionization experiments have been carried out on thymine-water clusters in the gas phase. Metastable H2O loss from T+(H2O)n was observed at n ≥ 3 only. Ab initio quantum-chemical calculations of a large range of optimized T+(H2O)n conformers have been performed up to n = 4, enabling binding energies of water to be derived. These decrease smoothly with n, consistent with the general trend of increasing metastable H2O loss in the experimental data. The lowest-energy conformers of T+(H2O)3 and T+(H2O)4 feature intermolecular bonding via charge-dipole interactions, in contrast with the purely hydrogen-bonded neutrals. We found no evidence for a closed hydration shell at n = 4, also contrasting with studies of neutral clusters.
Published: 2017
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25. Studies on GeF 4 Valence and Rydberg States by Electron Impact Spectroscopy and Ab Initio Calculations

Author: Hidetoshi Kato, Shohei Ohtomi, Masamitsu Hoshino, Paulo Limão-Vieira, Denis Duflot, Atsushi Suga, H. Tanaka, Department of Physics, Sophia University, Sophia University [Tokyo], The University of Tokyo (UTokyo), Physico-Chimie Moléculaire Théorique (PCMT), Laboratoire de Physique des Lasers, Atomes et Molécules - UMR 8523 (PhLAM), Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Centro de Física e Investigação Tecnológica [Lisboa] (CEFITEC), Departamento de Fìsica [Lisboa] (DF), Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), and Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)
Subjects: Valence (chemistry), Chemistry, 02 engineering and technology, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, 7. Clean energy, Molecular physics, 0104 chemical sciences, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, symbols.namesake, Ab initio quantum chemistry methods, Excited state, Rydberg atom, Rydberg formula, symbols, Singlet state, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Physical and Theoretical Chemistry, Ionization energy, Atomic physics, 0210 nano-technology, Electron ionization, ComputingMilieux_MISCELLANEOUS
Abstract: Electron energy loss (EEL) spectra of GeF4 have been measured with incident electrons at 100 eV for 5° scattering angle and at 30 eV for 30° scattering angle, while sweeping the energy loss over the range 7.0–18.0 eV. Low-lying excited triplet, singlet, valence, and Rydberg states are investigated and the assignments supported by quantum chemical ab initio calculations. This provides the first comprehensive investigation of all singlet and triplet excited electronic states of germanium tetrafluoride up to the first ionization energy. The Rydberg series converging to the (lowest) ionization energy limits of GeF4 are also identified according to the magnitude of the quantum defects (δ).
Published: 2016
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26. Experimental and Theoretical Studies on the Electronic State Spectroscopy of Methanol

Author: Lange, Emanuele, Duflot, Denis, Limão-Vieira, Paulo, Ferreira Da Silva, F., Physico-Chimie Moléculaire Théorique (PCMT), Laboratoire de Physique des Lasers, Atomes et Molécules - UMR 8523 (PhLAM), Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Centro de Física e Investigação Tecnológica [Lisboa] (CEFITEC), Departamento de Fìsica [Lisboa] (DF), Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA), and ANR-11-LABX-0005,Cappa,Physiques et Chimie de l'Environnement Atmosphérique(2011)
Subjects: [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], ComputingMilieux_MISCELLANEOUS
Abstract: International audience
Published: 2016

27. Valence and lowest Rydberg electronic states of phenol investigated by synchrotron radiation and theoretical methods

Author: Michael J. Brunger, Paulo Limão-Vieira, F. Ferreira da Silva, Nykola C. Jones, Małgorzata A. Śmiałek, E. Lange, Darryl Jones, Søren Vrønning Hoffmann, Denis Duflot, Centro de Física e Investigação Tecnológica [Lisboa] (CEFITEC), Departamento de Fìsica [Lisboa] (DF), Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA), Physico-Chimie Moléculaire Théorique (PCMT), Laboratoire de Physique des Lasers, Atomes et Molécules - UMR 8523 (PhLAM), Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Department of Physics and Astronomy [Aarhus], Aarhus University [Aarhus], Atomic Physics Division, Department of Atomic Physics and Luminescence, Faculty of Applied Physics and Mathematics, Gdańsk University of Technology (GUT), School of Chemical and Physical Sciences, Flinders Universiy, School of Engineering and Physical Sciences, James Cook University (JCU), ANR-11-LABX-0005,Cappa,Physiques et Chimie de l'Environnement Atmosphérique(2011), CeFITec – Centro de Física e Investigação Tecnológica, and DF – Departamento de Física
Subjects: General Physics and Astronomy, 010402 general chemistry, 01 natural sciences, 7. Clean energy, Spectral line, symbols.namesake, 0103 physical sciences, SPECTRA, Physical and Theoretical Chemistry, ABSORPTION CROSS-SECTIONS, Valence (chemistry), SPECTROSCOPY, 010304 chemical physics, Chemistry, VUV PHOTOABSORPTION, AB-INITIO, Photodissociation, GAUSSIAN-BASIS SETS, PHOTODISSOCIATION, 0104 chemical sciences, UV, Photoexcitation, Coupled cluster, Rydberg formula, symbols, Density functional theory, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Atomic physics, HYDROCARBONS, MONOSUBSTITUTED BENZENES, Excitation
Abstract: P.L.V. and F.F.S. acknowledge the Portuguese National Funding Agency FCT-MCTES through Grant Nos. UID/FIS/00068/2013 and IF-FCT IF/00380/2014. E.L. acknowledges the Brazilian Agency Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq) and the Science Without Borders Programme for opportunities to study abroad. D.D. acknowledges support from the CaPPA project (Chemical and Physical Properties of the Atmosphere), funded by the French National Research Agency (ANR) through the PIA (Programme d'Investissement d'Avenir) under Contract No. ANR-10-LABX-005 and by the Regional Council "Nord-Pas de Calais" and the "European Funds for Regional Economic Development" (FEDER). M.A.S. would like to acknowledge the Visiting Research Fellow position at The Open University. This work was performed using HPC resources from GENCI-CINES (Grant No. 2015-088620). The Centre de Ressources Informatiques (CRI) of the Universite of Lille also provided computing time. The authors wish to acknowledge the beam time at the ISA synchrotron at Aarhus University, Denmark. We also acknowledge the financial support provided by the European Community's Seventh Framework Programme (No. FP7/2007-2013) CALIPSO under Grant Agreement No. 312284. M.J.B. acknowledges financial support provided through the Australian Research Council (ARC). We present the experimental high-resolution vacuum ultraviolet (VUV) photoabsorption spectra of phenol covering for the first time the full 4.3-10.8 eV energy-range, with absolute cross sections determined. Theoretical calculations on the vertical excitation energies and oscillator strengths were performed using time-dependent density functional theory and the equation-of-motion coupled cluster method restricted to single and double excitations level. These have been used in the assignment of valence and Rydberg transitions of the phenol molecule. The VUV spectrum reveals several new features not previously reported in the literature, with particular reference to the 6.401 eV transition, which is here assigned to the 3s sigma/sigma*(OH) publishersversion published
Published: 2016
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28. Toluene Valence and Rydberg Excitations as Studied by ab initio Calculations and Vacuum Ultraviolet (VUV) Synchrotron Radiation

Author: Paulo Limão-Vieira, Benilde Simões Mendes, Denis Duflot, Søren Vrønning Hoffmann, C. Serralheiro, Nykola C. Jones, Nicholas J Mason, F. Ferreira da Silva, Centro de Engenharia Mecânica e Sustentabilidade de Recursos (MEtRICS), Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA), Physico-Chimie Moléculaire Théorique (PCMT), Laboratoire de Physique des Lasers, Atomes et Molécules - UMR 8523 (PhLAM), Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Department of Physics and Astronomy [Aarhus], Aarhus University [Aarhus], School of Physical Sciences [Milton Keynes], Faculty of Science, Technology, Engineering and Mathematics [Milton Keynes], The Open University [Milton Keynes] (OU)-The Open University [Milton Keynes] (OU), Centro de Física e Investigação Tecnológica [Lisboa] (CEFITEC), Departamento de Fìsica [Lisboa] (DF), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Portuguese National Funding Agency FCT-MEC through researcher and sabbatical grants, IF-FCT IF/00380/2014 and SFRH/BSAB/105792/2014, research grants PTDC/FIS-ATO/1832/2012 and UID/FIS/00068/2013, and ANR-11-LABX-0005,Cappa,Physiques et Chimie de l'Environnement Atmosphérique(2011)
Subjects: Vacuum, 010504 meteorology & atmospheric sciences, Ultraviolet Rays, Synchrotron radiation, Electrons, 7. Clean energy, 01 natural sciences, Electron spectroscopy, symbols.namesake, Ab initio quantum chemistry methods, 0103 physical sciences, Molecule, Physical and Theoretical Chemistry, Spectroscopy, 0105 earth and related environmental sciences, Photolysis, Valence (chemistry), 010304 chemical physics, Atmosphere, Chemistry, Photodissociation, Absorption, Radiation, 13. Climate action, Rydberg formula, symbols, Quantum Theory, Spectrophotometry, Ultraviolet, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Atomic physics, Synchrotrons, Toluene
Abstract: International audience; The electronic spectroscopy of isolated toluene in the gas phase has been investigated using high-resolution photoabsorption spectroscopy in the 4.0–10.8 eV energy range, with absolute cross-section measurements derived. We present the first set of ab initio calculations (vertical energies and oscillator strengths), which we use in the assignment of valence and Rydberg transitions of the toluene molecule. The spectrum reveals several new features not previously reported in the literature, with particular relevance to 7.989 and 8.958 eV, which are here tentatively assigned to the π*(17a′) ← σ(15a′) and 1π*(10a″) ← 1π(14a′) transitions, respectively. The measured absolute photoabsorption cross sections have been used to calculate the photolysis lifetime of toluene in the upper stratosphere (20–50 km).
Published: 2015
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29. Electronic State Spectroscopy of Halothane As Studied by ab Initio Calculations, Vacuum Ultraviolet (VUV) Synchrotron Radiation and Electron Scattering Methods

Author: Denis Duflot, Paulo Limão-Vieira, Nykola C. Jones, A. M. Ferreira-Rodrigues, G. G. B. de Souza, Samuel Eden, Flavio N. Rodrigues, Søren Vrønning Hoffmann, F. Ferreira da Silva, Nicholas J Mason, Centro de Física e Investigação Tecnológica [Lisboa] (CEFITEC), Departamento de Fìsica [Lisboa] (DF), Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA), Physico-Chimie Moléculaire Théorique (PCMT), Laboratoire de Physique des Lasers, Atomes et Molécules - UMR 8523 (PhLAM), Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Department of Physics and Astronomy [Aarhus], Aarhus University [Aarhus], Instituto de Química, Universidade de São Paulo, Departamento da Ciência da Natureza e Matemática, Instituto Federal de Educação, Ciência e Tecnologia do Rio de Janeiro, DCN, Instituto de Biociências, Universidade Federal do Estado do Rio de Janeiro (UNIRIO), School of Physical Sciences [Milton Keynes], Faculty of Science, Technology, Engineering and Mathematics [Milton Keynes], The Open University [Milton Keynes] (OU)-The Open University [Milton Keynes] (OU), Portuguese National Funding Agency FCT-MEC through researcher and sabbatical grants, IF-FCT IF/00380/2014 and SFRH/BSAB/105792/2014, research grants PTDC/FIS-ATO/1832/2012 and UID/FIS/00068/2013, British EPSRC through a Life Sciences Interface Fellowship (EP/E039618/1), a Career Acceleration Fellowship (EP/J002577/1), Research Grant (EP/L002191/1), and ANR-11-LABX-0005,Cappa,Physiques et Chimie de l'Environnement Atmosphérique(2011)
Subjects: Valence (chemistry), Vacuum, Absorption spectroscopy, Ultraviolet Rays, Chemistry, Photoelectron Spectroscopy, Photodissociation, Synchrotron radiation, Electrons, 7. Clean energy, symbols.namesake, 13. Climate action, Ab initio quantum chemistry methods, Rydberg formula, symbols, Quantum Theory, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Physical and Theoretical Chemistry, Atomic physics, Halothane, Spectroscopy, Electron scattering, Synchrotrons
Abstract: International audience; We present the first set of ab initio calculations (vertical energies and oscillator strengths) of the valence and Rydberg transitions of the anaesthetic compound halothane (CF3CHBrCl). These results are complemented by high-resolution vacuum ultraviolet photoabsorption measurements over the wavelength range 115–310 nm (10.8–4.0 eV). The spectrum reveals several new features that were not previously reported in the literature. Spin–orbit effects have been considered in the calculations for the lowest-lying states, allowing us to explain the broad nature of the 6.1 and 7.5 eV absorption bands assigned to σ*(C–Br) ← nBr and σ*(C–Cl) ← nCl transitions. Novel absolute photoabsorption cross sections from electron scattering data were derived in the 4.0–40.0 eV range. The measured absolute photoabsorption cross sections have been used to calculate the photolysis lifetime of halothane in the upper stratosphere (20–50 km).
Published: 2015
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30. Highly efficient end-side-pumped Nd:YAG solar laser by a heliostat-parabolic mirror system

Author: Dawei Liang, Emmanuel Guillot, Joana Almeida, Cláudia R. Vistas, Centro de Física e Investigação Tecnológica [Lisboa] (CEFITEC), Departamento de Fìsica [Lisboa] (DF), Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA), Procédés, Matériaux et Energie Solaire (PROMES), Université de Perpignan Via Domitia (UPVD)-Centre National de la Recherche Scientifique (CNRS), and European Project: 312643,EC:FP7:INFRA,FP7-INFRASTRUCTURES-2012-1,SFERA-II(2014)
Subjects: Heliostat, Materials science, Physics::Optics, 02 engineering and technology, Laser pumping, 01 natural sciences, law.invention, 010309 optics, X-ray laser, Optics, law, 0103 physical sciences, Diode-pumped solid-state laser, Electrical and Electronic Engineering, Engineering (miscellaneous), [PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics], business.industry, Slope efficiency, 021001 nanoscience & nanotechnology, Solar energy, Laser, Atomic and Molecular Physics, and Optics, Nd:YAG laser, Optoelectronics, 0210 nano-technology, business
Abstract: We report a large improvement in the collection and slope efficiency of an Nd:YAG solar laser pumped by a heliostat–parabolic mirror system. A conical fused silica lens was used to further concentrate the solar radiation from the focal zone of a 2 m diameter primary concentrator to a Nd:YAG single-crystal rod within a conical pump cavity, which enabled multipass pumping to the active medium. A 56 W cw laser power was measured, corresponding to 21.1 W/m2 record-high solar laser collection efficiency with the heliostat–parabolic mirror system. 4.9% slope efficiency was calculated, corresponding to 175% enhancement over our previous result.
Published: 2015
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31. Electronic excitation to low-lying states of GeF4 molecule by electron impact: A comparative study with CF4 and SiF4 molecules

Author: A. Suga, M. Hoshino, S. Ohtomi, Hideaki Tanaka, Paulo Limão-Vieira, Denis Duflot, Hisatoyo Kato, Y Mochizuki, M. Matsui, Department of Physics, Sophia University, Sophia University [Tokyo], Physico-Chimie Moléculaire Théorique (PCMT), Laboratoire de Physique des Lasers, Atomes et Molécules - UMR 8523 (PhLAM), Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Centro de Física e Investigação Tecnológica [Lisboa] (CEFITEC), Departamento de Fìsica [Lisboa] (DF), Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), and Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)
Subjects: History, Range (particle radiation), Electron energy, 010304 chemical physics, Chemistry, Scattering, Electron energy loss spectroscopy, 010402 general chemistry, 01 natural sciences, Molecular physics, 0104 chemical sciences, Computer Science Applications, Education, 0103 physical sciences, Molecule, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Atomic physics, Spectroscopy, Electron ionization, Excitation, ComputingMilieux_MISCELLANEOUS
Abstract: International audience; We report on the measurements of the electron impact electronic excitation cross sections for XF4 (X = C, Si and Ge) molecules at 100 eV, 5° scattering angle and 30 eV, 30° in the electron energy loss range 8.0 - 18 eV. For a target of GeF4 molecule, the optically-forbidden behavior has been observed in the lower electron energy loss range.
Published: 2015
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32. Solar-pumped TEM00 mode Nd:YAG laser by a heliostat—Parabolic mirror system

Author: Dawei Liang, Cláudia R. Vistas, Joana Almeida, Emmanuel Guillot, Centro de Física e Investigação Tecnológica [Lisboa] (CEFITEC), Departamento de Fìsica [Lisboa] (DF), Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA), Procédés, Matériaux et Energie Solaire (PROMES), Université de Perpignan Via Domitia (UPVD)-Centre National de la Recherche Scientifique (CNRS), and European Project: 312643,EC:FP7:INFRA,FP7-INFRASTRUCTURES-2012-1,SFERA-II(2014)
Subjects: [PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics], Materials science, Renewable Energy, Sustainability and the Environment, business.industry, Laser pumping, Solar-pumped laser, Laser, Beam parameter product, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, law.invention, Optics, law, Nd:YAG laser, Diode-pumped solid-state laser, Optoelectronics, Laser beam quality, Laser power scaling, business
Abstract: Here we report a significant advance in solar-pumped laser beam brightness by pumping a 3 mm diameter Nd:YAG single-crystal rod with a heliostat-parabolic mirror system. The incoming solar radiation is first collected and focused by the system. A rectangular fused silica light guide and a 2D-CPC concentrator are then combined to further compress the concentrated solar radiation into the laser rod within a V-shaped pumping cavity. 4.4 W continuous-wave TEM 00 mode ( M 2 ≤1.05) 1064 nm solar laser power is finally produced, attaining 4.0 W laser beam brightness figure of merit, which is 2.1 times higher than the previous record by a Fresnel lens. 0.81% TEM 00 mode laser slope efficiency is achieved.
Published: 2015
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33. BF3 Valence and Rydberg States As Probed by Electron Energy Loss Spectroscopy and ab Initio Calculations

Author: Masamitsu Hoshino, Hidetoshi Kato, Paulo Limão-Vieira, H. Tanaka, A. Suga, Denis Duflot, Laboratoire de Physique des Lasers, Atomes et Molécules - UMR 8523 (PhLAM), Université de Lille-Centre National de la Recherche Scientifique (CNRS), The University of Tokyo (UTokyo), Centro de Física e Investigação Tecnológica [Lisboa] (CEFITEC), Departamento de Fìsica [Lisboa] (DF), Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA), Department of Physics, Sophia University, and Sophia University [Tokyo]
Subjects: Scattering, Chemistry, Oscillator strength, Electron energy loss spectroscopy, 02 engineering and technology, 021001 nanoscience & nanotechnology, 01 natural sciences, 7. Clean energy, symbols.namesake, Ab initio quantum chemistry methods, 0103 physical sciences, Rydberg formula, symbols, Singlet state, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Physical and Theoretical Chemistry, Atomic physics, Ionization energy, 010306 general physics, 0210 nano-technology, Spectroscopy
Abstract: International audience; In this contribution we probe BF3 low-lying excited singlet states measured at 100 eV, 2.8° scattering angle and triplet states at 40 eV, 40° scattering angle, while sweeping the energy loss over the range 10.0-20.0 eV. The electronic state spectroscopy has been investigated and the assignments supported by quantum chemical calculations. This provides the first comprehensive investigation of all singlet and triplet excited electronic states of boron trifluoride up to the first ionization potential. A generalized oscillator strength analysis is employed to derive oscillator strength f0 value and integral cross sections (ICSs) from the corresponding differential cross sections (DCSs). The f0 value is compared with the optical oscillator strength (OOS) from photoabsorption, and the unscaled Born ICSs are then compared with relevant energy and binary-encounter and f-scaled Born cross section (BEf-scaling) results determined as a part of this investigation. The lowest n members of the Rydberg series have been assigned as converging to the lowest ionization energy limits of boron trifluoride and classified according to the magnitude of the quantum defects (δ).
Published: 2014
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34. Differential cross sections for intermediate-energy electron scattering from α-tetrahydrofurfuryl alcohol: Excitation of electronic-states

Author: P. A. Thorn, G. B. da Silva, Francisco J. Blanco, Gustavo García, H. V. Duque, Denis Duflot, Z. Pettifer, Jacques Delwiche, Kuru Ratnavelu, Darryl Jones, Ronald D. White, M.-J. Hubin-Franskin, Paulo Limão-Vieira, Michael J. Brunger, Luca Chiari, M. C. A. Lopes, CaPS (CaPS), Flinders University, Departamento de Física, Universidade Federal de Juiz de Fora (UFJF), Universidade Federal de Mato Grosso, Centro de Física e Investigação Tecnológica [Lisboa] (CEFITEC), Departamento de Fìsica [Lisboa] (DF), Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA), Laboratoire de Physique des Lasers, Atomes et Molécules - UMR 8523 (PhLAM), Université de Lille-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Spectroscopie d'Electrons Diffusés, Université de Liège, Departamento de Física Atómica, Molecular y Nuclear, Universidad Complutense de Madrid = Complutense University of Madrid [Madrid] (UCM), Instituto de Física Fundamental [Madrid] (IFF), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Universidade de Juíz de Fora, Institute of Mathematical Sciences, University of Malaya, School of Engineering and Physical Sciences, James Cook University (JCU), School of Chemical and Physical Sciences, Flinders Universiy, Universidade Federal de Juiz de Fora, Faculdade de Ciências e Tecnologia (FCT NOVA), Universidade Nova de Lisboa = NOVA University of Lisboa (NOVA)-Universidade Nova de Lisboa = NOVA University of Lisboa (NOVA)-Faculdade de Ciências e Tecnologia (FCT NOVA), Universidade Nova de Lisboa = NOVA University of Lisboa (NOVA)-Universidade Nova de Lisboa = NOVA University of Lisboa (NOVA), Physico-Chimie Moléculaire Théorique (PCMT), Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Departamento de Fisica Atomica, Molecular y Nuclear, Universidad Complutense de Madrid [Madrid] (UCM), Consejo Superior de Investigaciones Científicas [Spain] (CSIC), ANR-11-LABX-0005/11-LABX-0005,Cappa,Physiques et Chimie de l’Environnement Atmosphérique(2011), and University of Malaya = Universiti Malaya [Kuala Lumpur, Malaisie] (UM)
Subjects: Range (particle radiation), Chemistry, General Physics and Astronomy, Optical theorem, Electrons, Electron, Models, Theoretical, 3. Good health, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, symbols.namesake, Cross section (physics), Energy Transfer, Rydberg formula, symbols, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Physical and Theoretical Chemistry, Atomic physics, Electronics, Furans, Electron scattering, Excitation, Electron ionization
Abstract: 9 pags.; 5 figs.; 3 tabs., We report on measurements of differential cross sections (DCSs) for electron impact excitation of a series of Rydberg electronic-states in α-tetrahydrofurfuryl alcohol (THFA). The energy range of these experiments was 20-50 eV, while the scattered electron was detected in the 10°-90° angular range. There are currently no other experimental data or theoretical computations against which we can directly compare the present measured results. Nonetheless, we are able to compare our THFA DCSs with earlier cross section measurements for Rydberg-state electronic excitation for tetrahydrofuran, a similar cyclic ether, from Do et al. [J. Chem. Phys. 134, 144302 (2011)]. In addition, >rotationally averaged>elastic DCSs, calculated using our independent atom model with screened additivity rule correction approach are also reported. Those latter results give integral cross sections consistent with the optical theorem, and supercede those from the only previous study of Milosavljevićet al. [Eur. Phys. J. D 40, 107 (2006)]. © 2014 AIP Publishing LLC., Spanish Ministerio de Economia y Competitividad under Project No. FIS2012-31230) funding agencies who financially supported various aspects of this work
Published: 2014
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35. Electronic States of Tetrahydrofurfuryl Alcohol (THFA) As Studied by VUV Spectroscopy and Ab Initio Calculations

Author: Denis Duflot, Paulo Limão-Vieira, Jacques Delwiche, Luca Chiari, M. C. A. Lopes, Michael J. Brunger, M.-J. Hubin-Franskin, Søren Vrønning Hoffmann, Darryl Jones, Centro de Física e Investigação Tecnológica [Lisboa] (CEFITEC), Departamento de Fìsica [Lisboa] (DF), Faculdade de Ciências e Tecnologia (FCT NOVA), Universidade Nova de Lisboa = NOVA University of Lisboa (NOVA)-Universidade Nova de Lisboa = NOVA University of Lisboa (NOVA)-Faculdade de Ciências e Tecnologia (FCT NOVA), Universidade Nova de Lisboa = NOVA University of Lisboa (NOVA)-Universidade Nova de Lisboa = NOVA University of Lisboa (NOVA), Physico-Chimie Moléculaire Théorique (PCMT), Laboratoire de Physique des Lasers, Atomes et Molécules - UMR 8523 (PhLAM), Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Spectroscopie d'Electrons Diffusés, Université de Liège, Department of Physics and Astronomy [Aarhus], Aarhus University [Aarhus], School of Chemical and Physical Sciences, Flinders Universiy, School of Engineering and Physical Sciences, James Cook University (JCU), Departamento de Física, Universidade Federal de Juiz de Fora, ANR-11-LABX-0005/11-LABX-0005,Cappa,Physiques et Chimie de l’Environnement Atmosphérique(2011), Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA), Université de Lille-Centre National de la Recherche Scientifique (CNRS), Institute for Storage Ring Facilities, CaPS (CaPS), Flinders University, Universidade de Juíz de Fora, and ANR-11-LABX-0005,Cappa,Physiques et Chimie de l'Environnement Atmosphérique(2011)
Subjects: education.field_of_study, 010304 chemical physics, Chemistry, Photoemission spectroscopy, Population, Electrons, 010402 general chemistry, 01 natural sciences, Electron spectroscopy, 0104 chemical sciences, Ion, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Ab initio quantum chemistry methods, Excited state, 0103 physical sciences, Quantum Theory, Spectrophotometry, Ultraviolet, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Physical and Theoretical Chemistry, Ionization energy, Atomic physics, Furans, education, Spectroscopy
Abstract: International audience; : The electronic spectroscopy of isolated tetrahydrofurfuryl alcohol (THFA) in the gas phase has been investigated using high-resolution photoabsorption spectroscopy in the 5.0-10.8 eV energy-range, with absolute cross-section measurements derived. The He(I) photoelectron spectrum was also collected to quantify ionization energies in the 9-16 eV spectral region. These experiments are supported by the first high-level ab initio calculations performed on the excited states of the neutral molecule and on the ground and excited state of the positive ion. The good agreement between the theoretical results and the measurements allows us to quantify for the first time the electronic-state spectroscopy of THFA. The present work also considers the question of the lowest energy conformers of the molecule and its population distribution at room temperature.
Published: 2014
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36. Biomedical Engineering Systems and Technologies, 7th International Joint Conference, BIOSTEC2014, Extended Selected Papers

Author: Cliquet Jr, Alberto, Secca, Mário Forjaz, Schier, Jan, PASTOR, Oscar, Sinoquet, Christine, Loose, Harald, Bienkiewicz, Marta, Verdier, Christine, Plantier, Guy, Schultz, Tania, Fred, Ana, Gamboa, Hugo, University of São Paulo & University of Campinas, Brazil, University of São Paulo, Centro de Física e Investigação Tecnológica [Lisboa] (CEFITEC), Departamento de Fìsica [Lisboa] (DF), Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA), Institute of Information Theory and Automation of the Czech Academy of Sciences (UTIA / CAS), Czech Academy of Sciences [Prague] (CAS), Université de Valence, University of Valencia, LINA, Université de Nantes (UN), Brandenburg University of Applied Sciences, Technische Universität Munchen - Université Technique de Munich [Munich, Allemagne] (TUM), University Joseph Fourier Grenoble, France, University Joseph Fourier Grenoble, ESEO-GSII (GSII), ESEO-Tech, and Université Bretagne Loire (UBL)-Université Bretagne Loire (UBL)
Subjects: [SDV.BIBS]Life Sciences [q-bio]/Quantitative Methods [q-bio.QM], ComputingMilieux_MISCELLANEOUS
Abstract: International audience
Published: 2014

37. Valence and ionic lowest-lying electronic states of ethyl formate as studied by high-resolution vacuum ultraviolet photoabsorption, He(I) photoelectron spectroscopy, and ab initio calculations

Author: Denis Duflot, Søren Vrønning Hoffmann, Paulo Limão-Vieira, Małgorzata A. Śmiałek, Jacques Delwiche, Marta Łabuda, Julien Guthmuller, Nykola C. Jones, Marie-Jeanne Hubin-Franskin, Nicholas J Mason, Atomic Physics Division, Department of Atomic Physics and Luminescence, Faculty of Applied Physics and Mathematics, Gdańsk University of Technology (GUT), Laboratoire de Spectroscopie d'Electrons Diffusés, Université de Liège, Laboratoire de Physique des Lasers, Atomes et Molécules - UMR 8523 (PhLAM), Université de Lille-Centre National de la Recherche Scientifique (CNRS), Centro de Física e Investigação Tecnológica [Lisboa] (CEFITEC), Departamento de Fìsica [Lisboa] (DF), Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), and Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)
Subjects: Valence (chemistry), 010304 chemical physics, Photoemission spectroscopy, Photodissociation, General Physics and Astronomy, 010402 general chemistry, 01 natural sciences, 7. Clean energy, Molecular physics, Ethyl formate, 0104 chemical sciences, chemistry.chemical_compound, symbols.namesake, X-ray photoelectron spectroscopy, chemistry, Ab initio quantum chemistry methods, 0103 physical sciences, Rydberg formula, symbols, Physics::Atomic and Molecular Clusters, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Physical and Theoretical Chemistry, Ionization energy, Physics::Chemical Physics, ComputingMilieux_MISCELLANEOUS
Abstract: The highest resolution vacuum ultraviolet photoabsorption spectrum of ethyl formate, C2H5OCHO, yet reported is presented over the wavelength range 115.0–275.5 nm (10.75–4.5 eV) revealing several new spectral features. Valence and Rydberg transitions and their associated vibronic series, observed in the photoabsorption spectrum, have been assigned in accordance with new ab initio calculations of the vertical excitation energies and oscillator strengths. Calculations have also been carried out to determine the ionization energies and fine structure of the lowest ionic state of ethyl formate and are compared with a newly recorded He(I) photoelectron spectrum (from 10.1 to 16.1 eV). New vibrational structure is observed in the first photoelectron band. The photoabsorption cross sections have been used to calculate the photolysis lifetime of ethyl formate in the upper stratosphere (20–50 km).
Published: 2014
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38. Multi-photon and electron impact ionisation studies of reactivity in adenine–water clusters

Author: Samuel Eden, J. Tabet, E. Jabbour Al Maalouf, Nigel J. Mason, Marcin Dampc, P J M van der Burgt, J. C. Poully, M. Ryszka, B. Barc, Paulo Limão-Vieira, R. Parajuli, P. Cahillane, Z el Otell, Centre de recherche sur les Ions, les MAtériaux et la Photonique (CIMAP - UMR 6252), Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Caen Normandie (UNICAEN), Normandie Université (NU), Centro de Física e Investigação Tecnológica [Lisboa] (CEFITEC), Departamento de Fìsica [Lisboa] (DF), Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA), Centre of Molecular and Optical Sciences [Milton Keynes] (CeMOS), Department of Physics and Astronomy [Milton Keynes], The Open University [Milton Keynes] (OU)-The Open University [Milton Keynes] (OU), Department of Physics and Astronomy [UCL London], University College of London [London] (UCL), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), and Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Experimental Physics, [PHYS.PHYS.PHYS-BIO-PH]Physics [physics]/Physics [physics]/Biological Physics [physics.bio-ph], Protonation, 010402 general chemistry, Mass spectrometry, Photochemistry, 01 natural sciences, Dissociation (chemistry), Ion, [CHIM.ANAL]Chemical Sciences/Analytical chemistry, Computational chemistry, 0103 physical sciences, Physical and Theoretical Chemistry, Instrumentation, ComputingMilieux_MISCELLANEOUS, Spectroscopy, Electron ionization, 010304 chemical physics, Chemistry, [PHYS.PHYS.PHYS-ATM-PH]Physics [physics]/Physics [physics]/Atomic and Molecular Clusters [physics.atm-clus], Intermolecular force, Condensed Matter Physics, 0104 chemical sciences, Radical ion, Excited state, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], [CHIM.RADIO]Chemical Sciences/Radiochemistry
Abstract: Multi-photon ionisation (MPI) and electron impact ionisation (EII) mass spectrometry experiments have been carried out to probe unimolecular and intermolecular reactivities in hydrated adenine clusters. The effects of clustering with water on fragment ion production from adenine have been studied for the first time. While the observation of NH4+ fragments indicated the dissociation of protonated adenine, the dominant hydration effects were enhanced C4H4N4+ production and the suppression of dissociative ionisation pathways with high activation energies. These observations can be attributed to energy removal from the excited adenine radical cation via cluster dissociation. Comparisons of MPI and EII measurements provided the first experimental evidence supporting hypoxanthine formation in adenine–water clusters via theoretically predicted barrierless deamination reactions in closed shell complexes.
Published: 2014
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39. BIOIMAGING 2014 - Proceedings of the International Conference on Bioimaging, ESEO, Angers, Loire Valley, France, 3-6 March, 2014

Author: Secca, Mário Forjaz, Schier, Jan, Plantier, Guy, Schultz, Tanja, Fred, Ana L. N., Gamboa, Hugo, Centro de Física e Investigação Tecnológica [Lisboa] (CEFITEC), Departamento de Fìsica [Lisboa] (DF), Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA), Institute of Information Theory and Automation of the Czech Academy of Sciences (UTIA / CAS), Czech Academy of Sciences [Prague] (CAS), ESEO-GSII (GSII), ESEO-Tech, Université Bretagne Loire (UBL)-Université Bretagne Loire (UBL), Interactive Systems Labs (ISL), Carnegie Mellon University [Pittsburgh] (CMU), Instituto Superior Técnico, Universidade Técnica de Lisboa (IST), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA), and Mário Forjaz Secca and Jan Schier and Guy Plantier and Tanja Schultz and Ana L. N. Fred and Hugo Gamboa
Subjects: [SDV.BBM.BP]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biophysics, ComputingMilieux_MISCELLANEOUS
Abstract: International audience; no abstract
Published: 2014

40. Studies of low-lying triplet states in 1,3-C4F6, c-C4F6 and 2-C4F6 by electron energy-loss spectroscopy and ab initio calculations

Author: Daisuke Mogi, T. Tanioka, Denis Duflot, Masamitsu Hoshino, Paulo Limão-Vieira, H. Tanaka, F. Ferreira da Silva, K. Anzai, Hidetoshi Kato, Centro de Física e Investigação Tecnológica [Lisboa] (CEFITEC), Departamento de Fìsica [Lisboa] (DF), Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA), Physico-Chimie Moléculaire Théorique (PCMT), Laboratoire de Physique des Lasers, Atomes et Molécules - UMR 8523 (PhLAM), Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Université de Lille-Centre National de la Recherche Scientifique (CNRS), Department of Physics, Sophia University, Sophia University [Tokyo], The University of Tokyo (UTokyo), Research & Marketing Management Dept., New Products Development Div., Kogyo Co., Ltd., and Shibukawa-Area Lab., Development Research Lab., New Products Development Div.
Subjects: Range (particle radiation), Chemistry, Electron energy loss spectroscopy, General Physics and Astronomy, 010402 general chemistry, 01 natural sciences, Potential energy, 0104 chemical sciences, Energy profile, Ab initio quantum chemistry methods, Excited state, 0103 physical sciences, Molecule, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Physical and Theoretical Chemistry, Atomic physics, 010306 general physics, Spectroscopy
Abstract: This Letter reports on the first measurements of the lowest lying triplet states as studied by electron energy loss spectroscopy for C 4 F 6 isomers, hexafluoro-1,3-butadiene (1,3-C 4 F 6 ), hexafluorocyclobutene (c-C 4 F 6 ) and hexafluoro-2-butyne (2-C 4 F 6 ). This study has been performed at an incident electron energy of 30 eV, 30°, whilst sweeping the energy loss over the range 2.0–15.0 eV. The electronic state spectroscopy has been investigated and the assignments supported by multi-reference quantum chemical calculations. The transition to the steepest electronic excited potential energy curve, is suggested to be dominant for 2-C 4 F 6 , due to the large broadening in its energy profile.
Published: 2013
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41. Side-pumped continuous-wave Cr:Nd:YAG ceramic solar laser

Author: Joana Almeida, Emmanuel Guillot, Dawei Liang, Centro de Física e Investigação Tecnológica [Lisboa] (CEFITEC), Departamento de Fìsica [Lisboa] (DF), Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA), Procédés, Matériaux et Energie Solaire (PROMES), Université de Perpignan Via Domitia (UPVD)-Centre National de la Recherche Scientifique (CNRS), European Project: 228296,EC:FP7:INFRA,FP7-INFRASTRUCTURES-2008-1,SFERA(2009), CeFITec – Centro de Física e Investigação Tecnológica, and DF – Departamento de Física
Subjects: [PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics], Materials science, Physics and Astronomy (miscellaneous), business.industry, ROD LASER, Slope efficiency, Energy conversion efficiency, General Engineering, General Physics and Astronomy, ND-YAG LASER, Laser, Rod, law.invention, ND/YAG LASER, Optics, LAMP, law, visual_art, Optical cavity, visual_art.visual_art_medium, Continuous wave, Ceramic, Laser power scaling, business
Abstract: International audience; To clarify the advantages of Cr:Nd:YAG ceramics rods in solar-pumped lasers, a fused silica light guide with rectangular cross-section is coupled to a compound V-shaped cavity within which a 7 mm diameter 0.1 at% Cr: 1.0 at% Nd:YAG ceramic rod is uniformly pumped. The highly concentrated solar radiation at the focal spot of a 2 m diameter stationary parabolic mirror is transformed into a uniform pump radiation by the light guide. Efficient pump light absorption is achieved by pumping uniformly the ceramic rod within the V-shaped cavity. Optimum pumping parameters and solar laser output powers are found through ZEMAX© non-sequential ray-tracing and LASCAD© laser cavity analysis codes. 33.6 W continuous-wave laser power is measured, corresponding to 1.32 times enhancement over our previous results with a 4 mm diameter Nd:YAG single-crystal rod. High slope efficiency of 2.6% is also registered. The solar laser output performances of both the ceramic and the single-crystal rods are finally compared, revealing the relative advantage of the Cr:Nd:YAG rod in conversion efficiency. Low scattering coefficient of 0.0018 cm-1 is deduced for the ceramic rod. Heat load is considered as a key factor affecting the ceramic laser output performance. Response to Reviewers: See attachment Answers to the Reviewers' comments: Dear Reviewer 1 Many thanks for your very helpful and insightful comments We would like to answer your comments one by one Reviewer #1: I believe that the paper presents an interesting result. However, there are many significant misunderstanding and unclear points which should be considered before further review. 1. In Fig.5, they are comparing ceramic Cr.Nd YAG and Nd YAG crystal data but two conditions are completely Powered by Editorial Manager® and Preprint Manager® from Aries Systems Corporation
Published: 2013
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42. Electron attachment to the dipeptide dialanine: influence of methylation on site selective dissociation reactions

Author: Violaine Vizcaino, Katrin Tanzer, F. Ferreira da Silva, Benjamin Puschnigg, Stefan E. Huber, Stephan Denifl, Michael Probst, Paul Scheier, Paulo Limão-Vieira, Institut für Ionenphysik und Angewandte Physik - Institute for Ion Physics and Applied Physics [Innsbruck], Leopold Franzens Universität Innsbruck - University of Innsbruck, Centro de Física e Investigação Tecnológica [Lisboa] (CEFITEC), Departamento de Fìsica [Lisboa] (DF), Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), and Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)
Subjects: General Physics and Astronomy, Electrons, 02 engineering and technology, 010402 general chemistry, Photochemistry, Methylation, 01 natural sciences, Dissociation (chemistry), Ion, chemistry.chemical_compound, Amide, Molecule, Physical and Theoretical Chemistry, Bond cleavage, ComputingMilieux_MISCELLANEOUS, Alanine, Dipeptide, Chemistry, Resonance, Dipeptides, Hydrogen atom, 021001 nanoscience & nanotechnology, 0104 chemical sciences, Crystallography, Quantum Theory, Gases, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], 0210 nano-technology
Abstract: Gas phase dissociative electron attachment (DEA) measurements with methyl-dialanine, C(7)H(14)N(2)O(3), are performed in a crossed electron-molecular beam experiment at high energy resolution (∼120 meV). Anion efficiency yields as a function of the incident electron energy are obtained for the most abundant fragments up to electron energies of ∼15 eV. There is no evidence of molecular anion formation whereas the dehydrogenated closed shell anion (M-H)(-) is one of the most dominant reaction products. Quantum chemical calculations are performed to investigate the electron attachment process and to elucidate site selective bond cleavage in the (M-H)(-) DEA-channel. Previous DEA studies on dialanine have shown that (M-H)(-) formation proceeds through abstraction of a hydrogen atom from the carboxyl and amide groups, contributing to two distinct resonances at 0.81 and 1.17 eV, respectively [D. Gschliesser, V. Vizcaino, M. Probst, P. Scheier and S. Denifl, Chem.-Eur. J., 2012, 18, 4613-4619]. Here we show that by methylation of the carboxyl group, all (calculated) thresholds for H-loss from the different sites in the dialanine molecule are shifted up to a maximum of 1.4 eV. The lowest lying resonance observed experimentally for (M-H)(-) remains operative from the amide group at the electron energy of 2.4 eV due to the methylation. We further study methylation-induced effects on the unimolecular dissociation leading to a variety of negatively charged DEA products.
Published: 2013
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43. Electronic excitation of C4F6 isomers by electron impact

Author: H. Tanaka, Hisatoyo Kato, Paulo Limão-Vieira, K. Anzai, Denis Duflot, T. Tanioka, M. Hoshino, Daisuke Mogi, Department of Physics, Sophia University, Sophia University [Tokyo], The University of Tokyo (UTokyo), Research & Marketing Management Dept., New Products Development Div., Kogyo Co., Ltd., Shibukawa-Area Lab., Development Research Lab., New Products Development Div., Laboratoire de Physique des Lasers, Atomes et Molécules - UMR 8523 (PhLAM), Université de Lille-Centre National de la Recherche Scientifique (CNRS), Centro de Física e Investigação Tecnológica [Lisboa] (CEFITEC), Departamento de Fìsica [Lisboa] (DF), Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), and Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)
Subjects: History, Chemistry, 02 engineering and technology, 021001 nanoscience & nanotechnology, 01 natural sciences, Spectral line, 3. Good health, Computer Science Applications, Education, 0103 physical sciences, Molecule, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Atomic physics, 010306 general physics, 0210 nano-technology, Differential (mathematics), Excitation, Electron ionization
Abstract: International audience; We have measured electronic excitation differential cross sections for C4F6 molecules isomers by electron impact. In the case of hexafluoro-1,3-butadiene we observed an optical forbidden transition at around 5 eV. The spectra of the three C4F6 isomers show the most intense band clearly shifted to lower energies when going from 2-C4F6, to c-C4F6 and to 1,3-C4F6.
Published: 2012
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44. Improvement in solar-pumped Nd:YAG laser beam brightness

Author: Emmanuel Guillot, Dawei Liang, Joana Almeida, Centro de Física e Investigação Tecnológica [Lisboa] (CEFITEC), Departamento de Fìsica [Lisboa] (DF), Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA), Procédés, Matériaux et Energie Solaire (PROMES), Université de Perpignan Via Domitia (UPVD)-Centre National de la Recherche Scientifique (CNRS), and European Project: 228296,EC:FP7:INFRA,FP7-INFRASTRUCTURES-2008-1,SFERA(2009)
Subjects: Brightness, [PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics], Materials science, Aperture, business.industry, Parabolic reflector, Slope efficiency, Physics::Optics, Fresnel lens, Laser, Atomic and Molecular Physics, and Optics, Electronic, Optical and Magnetic Materials, law.invention, Optics, law, Nd:YAG laser, Figure of merit, Optoelectronics, Electrical and Electronic Engineering, business
Abstract: Solar-pumped solid-state lasers are promising for renewable extreme-temperature material processing. Here we report a large improvement in solar laser beam brightness by pumping a thin Nd:YAG single crystal rod. A fused silica light guide of 14 mm×22 mm rectangular cross-section is used to both transmit and homogenize the concentrated solar radiation from the focal zone of a 2.88 m2 parabolic mirror to the entrance aperture of a modified 2D-CPC flooded pump cavity, within which a 4 mm diameter rod is efficiently pumped. 2.2% slope efficiency is reached. Laser beam brightness figure of merit B is three times higher than that of the most recent solar-pumped Nd:YAG laser by a Fresnel lens. The introduction of the rectangular cross-section light guide has also ensured a much more stable laser emission than previous pumping schemes.
Published: 2012
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45. Electronic state spectroscopy of 1,4-pentadiene as studied by VUV photoabsorption spectroscopy and ab initio calculations

Author: Søren Vrønning Hoffmann, S. Sério, Paulo Limão-Vieira, Denis Duflot, Nigel J. Mason, Y. Nunes, Centro de Física e Investigação Tecnológica [Lisboa] (CEFITEC), Departamento de Fìsica [Lisboa] (DF), Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA), Centre for Storage Ring Facilities [Aarhus] (ISA), Aarhus University [Aarhus], Dept. of Physics and Astronomy, The Open University [Milton Keynes] (OU), Laboratoire de Physique des Lasers, Atomes et Molécules - UMR 8523 (PhLAM), and Université de Lille-Centre National de la Recherche Scientifique (CNRS)
Subjects: Valence (chemistry), 010405 organic chemistry, Chemistry, Photodissociation, Ionic bonding, 010402 general chemistry, 01 natural sciences, 7. Clean energy, Spectral line, 0104 chemical sciences, Alkadienes, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, symbols.namesake, Ab initio quantum chemistry methods, Rydberg formula, symbols, Quantum Theory, Spectrophotometry, Ultraviolet, Physical and Theoretical Chemistry, Atomic physics, Spectroscopy, Conformational isomerism
Abstract: International audience; We present high resolution VUV photoabsorption spectra of 1,4-pentadiene, C(5)H(8), over the wavelength range 115-247 nm (10.8-5.0 eV). These spectra reveal several new features not previously reported in the literature. These measurements are complemented by the first ab initio calculations for the three most abundant conformational isomers of 1,4-pentadiene, C(5)H(8), which we then use in the assignment of valence and Rydberg transitions. Calculations of the two lowest energy ionic states of 1,4-pentadiene are also presented and compared with the experimental data available in the literature. The measured absolute photoabsorption cross sections have been used to calculate the photolysis lifetime of 1,4-pentadiene in the upper stratosphere (20-50 km).
Published: 2012
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46. Limonene: electronic state spectroscopy by high-resolution vacuum ultraviolet photoabsorption, electron scattering, He(I) photoelectron spectroscopy and ab initio calculations

Author: Jacques Delwiche, A. M. Ferreira Rodrigues, Denis Duflot, Flavio N. Rodrigues, Paulo Limão-Vieira, G. G. B. de Souza, Małgorzata A. Śmiałek, Nigel J. Mason, M.-J. Hubin-Franskin, S. Vrønning-Hoffmann, Atomic Physics Division, Department of Atomic Physics and Luminescence, Faculty of Applied Physics and Mathematics, Gdańsk University of Technology (GUT), Laboratoire de Spectroscopie d'Electrons Diffusés, Université de Liège, Laboratoire de Physique des Lasers, Atomes et Molécules - UMR 8523 (PhLAM), Université de Lille-Centre National de la Recherche Scientifique (CNRS), Dept. of Physics and Astronomy, The Open University [Milton Keynes] (OU), Institute for Storage Ring Facilities, Aarhus University [Aarhus], Centro de Física e Investigação Tecnológica [Lisboa] (CEFITEC), Departamento de Fìsica [Lisboa] (DF), Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), and Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)
Subjects: Vacuum, Photoemission spectroscopy, Ultraviolet Rays, General Physics and Astronomy, Electrons, 010402 general chemistry, 01 natural sciences, Helium, Absorption, symbols.namesake, X-ray photoelectron spectroscopy, Ab initio quantum chemistry methods, 0103 physical sciences, Cyclohexenes, Physical and Theoretical Chemistry, 010306 general physics, Spectroscopy, Photolysis, Chemistry, Terpenes, Photoelectron Spectroscopy, Resolution (electron density), 0104 chemical sciences, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Excited state, Rydberg formula, symbols, Quantum Theory, Atomic physics, Ionization energy, Limonene
Abstract: International audience; Electronic state spectroscopy of limonene has been investigated using vacuum ultraviolet photoabsorption spectroscopy in the energy range 5.0-10.8 eV. The availability of a high resolution photon beam (~0.075 nm) enabled detailed analysis of the vibrational progressions and allowed us to propose, for the first time, new assignments for several Rydberg series. Excited states located in the 7.5-8.4 eV region have been studied for the first time. A He(I) photoelectron spectrum has also been recorded from 8.2 to 9.5 eV and compared to previous low resolution works. A new value of 8.521 ± 0.002 eV for the ground ionic state adiabatic ionisation energy is proposed. Absolute photoabsorption cross sections were derived in the 10-26 eV range from electron scattering data. All spectra presented in this paper represent the highest resolution data yet reported for limonene. These experiments are complemented by new ab initio calculations performed for the three most abundant conformational isomers of limonene, which we then used in the assignment of the spectral bands.
Published: 2012
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47. Electronic states of F2CO as studied by electron energy-loss spectroscopy and ab initio calculations

Author: H. Tanaka, Hidetoshi Kato, Paulo Limão-Vieira, Denis Duflot, Y. Nunes, Department of Physics, Sophia University, Sophia University [Tokyo], Centro de Física e Investigação Tecnológica [Lisboa] (CEFITEC), Departamento de Fìsica [Lisboa] (DF), Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA), Laboratoire de Physique des Lasers, Atomes et Molécules - UMR 8523 (PhLAM), and Université de Lille-Centre National de la Recherche Scientifique (CNRS)
Subjects: 010304 chemical physics, Chemistry, Electron energy loss spectroscopy, 010402 general chemistry, 7. Clean energy, 01 natural sciences, 0104 chemical sciences, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Vibronic coupling, symbols.namesake, Ab initio quantum chemistry methods, Excited state, 0103 physical sciences, Rydberg formula, symbols, Physical and Theoretical Chemistry, Ionization energy, Atomic physics, Spectroscopy, Electron ionization
Abstract: International audience; This paper reports on the first measurements of the electron impact electronic excitation cross-sections for carbonyl fluoride, F(2)CO, measured at 30 eV, 10° and 100 eV, 5° scattering angle, while sweeping the energy loss over the range 5.0-18.0 eV. The electronic-state spectroscopy has been investigated and the assignments are supported by quantum chemical calculations. The energy bands above 9.0 eV and the vibrational progressions superimposed upon it have been observed for the first time. Vibronic coupling has been shown to play an important role dictating the nature of the observed excited states, especially for the low-lying energy region (6.0-8.0 eV). New experimental evidence for the 6(1)B(2) state proposed to have its maximum at 12.75 eV according to the vibrational excitation reported in this energy region (11.6-14.0 eV). The n = 3 members of the Rydberg series have been assigned converging to the lowest ionization energy limits, 13.02 eV ((2)B(2)), 14.09 eV ((2)B(1)), 16.10 ((2)B(2)), and 19.15 eV ((2)A(1)) reported for the first time and classified according to the magnitude of the quantum defects (δ).
Published: 2011
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48. Electronic state spectroscopy of methyl formate probed by high resolution VUV photoabsorption, He(i) photoelectron spectroscopy and ab initio calculations

Author: Paulo Limão-Vieira, Søren Vrønning Hoffmann, Jacques Delwiche, G. Martins, Denis Duflot, Nigel J. Mason, Y. Nunes, M.-J. Hubin-Franskin, Centro de Física e Investigação Tecnológica [Lisboa] (CEFITEC), Departamento de Fìsica [Lisboa] (DF), Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA), Dept. of Physics and Astronomy, The Open University [Milton Keynes] (OU), Laboratoire de Physique des Lasers, Atomes et Molécules - UMR 8523 (PhLAM), Université de Lille-Centre National de la Recherche Scientifique (CNRS), Institute for Storage Ring Facilities, Aarhus University [Aarhus], Laboratoire de Spectroscopie d'Electrons Diffusés, and Université de Liège
Subjects: 010304 chemical physics, Oscillator strength, Chemistry, Methyl formate, Photoemission spectroscopy, General Physics and Astronomy, 010402 general chemistry, 01 natural sciences, 7. Clean energy, Molecular electronic transition, 0104 chemical sciences, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, chemistry.chemical_compound, Ab initio quantum chemistry methods, 0103 physical sciences, Physics::Atomic and Molecular Clusters, Formate, Physical and Theoretical Chemistry, Rydberg state, Atomic physics, Physics::Chemical Physics, Spectroscopy
Abstract: The first ab initio calculations of the vertical excitation energies and oscillator strengths are\ud presented for the neutral electronic transitions of methyl formate, C2H4O2. The highest resolution VUV photoabsorption spectrum of the molecule yet reported is presented over the wavelength\ud range 115 to 310 nm (10.8 to 4.0 eV) revealing several new spectral features. Valence and Rydberg transitions and their associated vibronic series, observed in the photoabsorption spectrum, have been assigned in accordance with new theoretical results. The calculations have\ud been carried out to determine the excitation energies of the lowest energy ionic states of methyl formate and are compared with a newly recorded He(I) photoelectron spectrum (10.4 to 17.0 eV). New vibrational structure is observed in the first photoelectron band. The photoabsorption\ud cross-sections have been used to calculate the photolysis lifetime of methyl formate in the upper\ud stratosphere (20-50 km).
Published: 2010
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49. Valence shell electronic spectroscopy of isoprene studied by theoretical calculations and by electron scattering, photoelectron, and absolute photoabsorption measurements

Author: Paulo Limão-Vieira, Denis Duflot, G. Martins, Nigel J. Mason, G. G. B. de Souza, Søren Vrønning Hoffmann, Flavio N. Rodrigues, Samuel Eden, A. M. Ferreira-Rodrigues, M.-J. Hubin-Franskin, Jean-Pierre Flament, Jacques Delwiche, Centro de Física e Investigação Tecnológica [Lisboa] (CEFITEC), Departamento de Fìsica [Lisboa] (DF), Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA), Dept. of Physics and Astronomy, The Open University [Milton Keynes] (OU), Laboratoire de Physique des Lasers, Atomes et Molécules - UMR 8523 (PhLAM), Université de Lille-Centre National de la Recherche Scientifique (CNRS), Institute for Storage Ring Facilities, Aarhus University [Aarhus], Laboratoire de Spectroscopie d'Electrons Diffusés, and Université de Liège
Subjects: 010504 meteorology & atmospheric sciences, Photoemission spectroscopy, General Physics and Astronomy, Spectroscopy, Electron Energy-Loss, 01 natural sciences, 7. Clean energy, Electron spectroscopy, chemistry.chemical_compound, Hemiterpenes, Ab initio quantum chemistry methods, Pentanes, 0103 physical sciences, Butadienes, Physical and Theoretical Chemistry, Spectroscopy, Isoprene, 0105 earth and related environmental sciences, Valence (chemistry), Photolysis, 010304 chemical physics, Chemistry, Electron energy loss spectroscopy, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Quantum Theory, Thermodynamics, Atomic physics, Valence electron
Abstract: International audience; The first ab initio calculations (vertical energies and oscillator strengths) are reported for the neutral electronic transitions of isoprene (2-methyl-1,3-butadiene), CH(2)CHC(CH(3))CH(2). The VUV photoabsorption spectroscopy of the molecule is presented in the energy range 4.6 to 10.8 eV (270-125 nm) with the highest resolution yet reported above 6.05 eV, revealing new spectral features. Valence and Rydberg transitions have been assigned in accordance with the theoretical results and the associated vibronic series have been analysed. The absolute photoabsorption cross sections at energies below 6.89 eV have been used to calculate the photolysis lifetime of isoprene in the upper stratosphere (20-50 km). Electron energy loss spectroscopy (EELS) measurements have enabled further photoabsorption cross sections to be derived in the range 9-28 eV. The first ab initio calculations have been carried out to determine excitation energies to the lowest energy ionic states of isoprene. The calculations are compared with the He(i) photoelectron spectrum (8 to 17 eV) and new vibrational structure is observed in the first photoelectron band.
Published: 2009
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50. Electronic states of neutral and ionized tetrahydrofuran studied by VUV spectroscopy and ab initio calculations

Author: Bratislav P. Marinković, Aleksandar R. Milosavljević, Nigel J. Mason, Denis Duflot, Jacques Delwiche, M.-J. Hubin-Franskin, Søren Vrønning Hoffmann, Paulo Limão-Vieira, Alexandre Giuliani, Giuliani, Alexandre, Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), Centro de Física e Investigação Tecnológica [Lisboa] (CEFITEC), Departamento de Fìsica [Lisboa] (DF), Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Faculdade de Ciências e Tecnologia = School of Science & Technology (FCT NOVA), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA)-Universidade Nova de Lisboa = NOVA University Lisbon (NOVA), Laboratoire de Physique des Lasers, Atomes et Molécules - UMR 8523 (PhLAM), Université de Lille-Centre National de la Recherche Scientifique (CNRS), Laboratory for atomic collision processes, Czech Academy of Sciences [Prague] (CAS), Institute for Storage Ring Facilities, Aarhus University [Aarhus], Dept. of Physics and Astronomy, The Open University [Milton Keynes] (OU), Laboratoire de Spectroscopie d'Electrons Diffusés, Université de Liège, EU FP6 programme IA-SFS contract number R113-CT-2004-506008, and ESF EIPAM and ESF COST Action P9 (RADAM)
Subjects: Materials science, Photoemission spectroscopy, Population, 010402 general chemistry, 01 natural sciences, Electron spectroscopy, spectroscopie, Photoelectron spectra, Ab initio quantum chemistry methods, Ionization, 0103 physical sciences, Spectroscopy, education, Vacuum ultraviolet spectra, education.field_of_study, 010304 chemical physics, Rydberg states, Atomic and Molecular Physics, and Optics, 0104 chemical sciences, Theoretical and/or physical chemistry, Excited state, Ab initio calculations, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Atomic physics, Ground state, Chimie théorique et/ou physique
Abstract: International audience; The electronic spectroscopy of isolated tetrahydrofuran (THF) in the gas phase has been investigated using high-resolution photoabsorption spectroscopy in the 5.8-10.6 eV with absolute cross-section measurements derived. In addition, an electron energy loss spectrum was recorded at 100 eV and 10° over the 5-11.4 eV range. The He(I) photoelectron spectrum was also collected to quantify ionisation energies in the 9-16.1 eV spectral region. These experiments are supported by the first high-level ab initio calculations performed on the excited states of the neutral molecule and on the ground state of the positive ion. The excellent agreement between the theoretical results and the measurements allows us to solve several discrepancies concerning the electronic state spectroscopy of THF. The present work reconsiders the question of the lowest energy conformers of the molecule and its population distribution at room temperature.
Published: 2009
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