12 results on '"CRESU"'
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2. Conclusions: Future Challenges and Perspectives
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Rowe, Bertrand R., Canosa, A., Heard, D. E., Rowe consulting, Institut de Physique de Rennes (IPR), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), and University of Leeds
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Product detection ,[PHYS]Physics [physics] ,Absolute zero ,Energy transfer ,Open questions ,Quantum theory ,Nucleation ,Challenges ,CRESU ,Reaction kinetics ,Spectroscopy ,Astrochemistry - Abstract
International audience; The present chapter highlights the main discoveries and breakthroughs described in the previous chapters of this book that uniform supersonic flows have allowed during the last forty years in the field of physical chemistry. The accumulation of experimental data in the domain of very-low-temperature reaction kinetics has stimulated new developments in theoretical quantum chemistry and astrochemical modeling, some of which will be further emphasized. Although a considerable body of knowledge has been explored during these four decades, we will comment about the many remaining challenges and open questions that could be tackled further using CRESU environments. Exploring these fields should be facilitated in the near future thanks to the significant number of new instrumental diagnostic tools that are in development in several research groups worldwide. © 2022 by World Scientific Publishing Europe Ltd.
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- 2022
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3. Experimental and Theoretical Investigation on the OH + CH3C(O)CH3 Reaction at Interstellar Temperatures (T = 11.7–64.4 K)
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André Canosa, Daniel González, Bernabé Ballesteros, Elena Jiménez, José Albaladejo, Astrid Bergeat, Alberto García-Sáez, Raphaël Méreau, Françoise Caralp, María Antiñolo, Sergio Blázquez, Universidad de Castilla-La Mancha = University of Castilla-La Mancha (UCLM), Institut des Sciences Moléculaires (ISM), Université Montesquieu - Bordeaux 4-Université Sciences et Technologies - Bordeaux 1 (UB)-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique de Rennes (IPR), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), European Research Council, ERC SyG-610256European Cooperation in Science and Technology, COST CM1401Universidad de Castilla-La Mancha, UCLMCentre National de la Recherche Scientifique, CNRS, Universidad de Castilla-La Mancha (UCLM), Université Montesquieu - Bordeaux 4-Université Sciences et Technologies - Bordeaux 1-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université de Rennes 1 (UR1), and Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS)
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Atmospheric Science ,gas-phase kinetics ,Radical ,Analytical chemistry ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,7. Clean energy ,Article ,Chemical kinetics ,Orders of magnitude (specific energy) ,Geochemistry and Petrology ,Quantum tunnelling ,ultralow temperatures ,[PHYS]Physics [physics] ,Molecular cloud ,CRESU ,Pressure dependence ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Interstellar medium ,interstellar molecules ,13. Climate action ,Space and Planetary Science ,Potential energy surface ,Molecular physics ,0210 nano-technology - Abstract
International audience; The rate coefficient, k(T), for the gas-phase reaction between OH radicals and acetone CH3C(O)CH3, has been measured using the pulsed CRESU (French acronym for Reaction Kinetics in a Uniform Supersonic Flow) technique (T = 11.7-64.4 K). The temperature dependence of k(T = 10-300 K) has also been computed using a RRKM-Master equation analysis after partial revision of the potential energy surface. In agreement with previous studies we found that the reaction proceeds via initial formation of two prereactive complexes both leading to H2O + CH3C(O)CH2 by H-abstraction tunneling. The experimental k(T) was found to increase as temperature was lowered. The measured values have been found to be several orders of magnitude higher than k(300 K). This trend is reproduced by calculations, with an especially good agreement with experiments below 25 K. The effect of total gas density on k(T) has been explored. Experimentally, no pressure dependence of k(20 K) and k(64 K) was observed, while k(50 K) at the largest gas density 4.47 × 1017 cm-3 is twice higher than the average values found at lower densities. The computed k(T) is also reported for 103 cm-3 of He (representative of the interstellar medium). The predicted rate coefficients at 10 K surround the experimental value which appears to be very close to that of the low pressure regime prevailing in the interstellar medium. For gas-phase model chemistry of interstellar molecular clouds, we suggest using the calculated value of 1.8 × 10-10 cm3 molecule-1 s-1 at 10 K, and the reaction products are water and CH3C(O)CH2 radicals. © 2019 American Chemical Society.
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- 2019
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4. HIGH-TEMPERATURE HYPERSONIC LAVAL NOZZLE FOR NON-LTE CAVITY RINGDOWN SPECTROSCOPY
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Samir Kassi, Abdessamad Benidar, Robert Georges, Vinayak Kulkarni, Shuvayan Brahmachary, Nicolas Suas-David, Christine Charles, Eszter Dudas, Institut de Physique de Rennes (IPR), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), Indian Institute of Technology Guwahati (IIT Guwahati), Laboratoire Interdisciplinaire de Physique [Saint Martin d’Hères] (LIPhy ), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Australian National University (ANU), ANR project e-PYTHEAS French National Research Agency (ANR) [ANR-16-CE31-0 0 05], CEFIPRA project [6005-N], Programme National 'Physique et Chimie du Milieu Interstellaire' (PCMI) of CNRS/INSU, INC/INP - CEA, CNES Centre National D'etudes Spatiales, CNES PERSEUS student program, ANR-16-CE31-0005,e-PYTHEAS,Etude des hydrocarbures en émission et absorption dasn les exoplanètes à haute température(2016), Université de Rennes 1 (UR1), and Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS)
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Hypersonic speed ,Materials science ,Population ,Nozzle ,General Physics and Astronomy ,Pitot tube ,010402 general chemistry ,01 natural sciences ,law.invention ,symbols.namesake ,law ,0103 physical sciences ,Vibrational energy relaxation ,Physical and Theoretical Chemistry ,education ,Spectroscopy ,[PHYS]Physics [physics] ,education.field_of_study ,010304 chemical physics ,Rotational temperature ,CRESU ,0104 chemical sciences ,Mach number ,symbols ,Oblique shock ,Atomic physics ,Molecular physics - Abstract
International audience; A small dimension Laval nozzle connected to a compact high enthalpy source equipped with cavity ringdown spectroscopy (CRDS) is used to produce vibrationally hot and rotationally cold high-resolution infrared spectra of polyatomic molecules in the 1.67 mu m region. The Laval nozzle was machined in isostatic graphite, which is capable of withstanding high stagnation temperatures. It is characterized by a throat diameter of 2 mm and an exit diameter of 24 mm. It was designed to operate with argon heated up to 2000 K and to produce a quasi-unidirectional flow to reduce the Doppler effect responsible for line broadening. The hypersonic flow was characterized using computational fluid dynamics simulations, Pitot measurements, and CRDS. A Mach number evolving from 10 at the nozzle exit up to 18.3 before the occurrence of a first oblique shock wave was measured. Two different gases, carbon monoxide (CO) and methane (CH4), were used as test molecules. Vibrational (T-vib) and rotational (T-rot) temperatures were extracted from the recorded infrared spectrum, leading to T-vib = 1346 +/- 52 K and T-rot = 12 +/- 1 K for CO. A rotational temperature of 30 +/- 3 K was measured for CH4, while two vibrational temperatures were necessary to reproduce the observed intensities. The population distribution between vibrational polyads was correctly described with TvibI=894 +/- 47K, while the population distribution within a given polyad (namely, the dyad or the pentad) was modeled correctly by TvibII=54 +/- 4K, testifying to a more rapid vibrational relaxation between the vibrational energy levels constituting a polyad.
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- 2021
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5. Gas Phase Reactivity of the CN Radical with Methyl Amines at Low Temperatures (23–297 K): A Combined Experimental and Theoretical Investigation
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Chantal Sleiman, André Canosa, Dahbia Talbi, Gisèle El Dib, Institut de Physique de Rennes (IPR), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Univers et Particules de Montpellier (LUPM), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Montpellier 2 - Sciences et Techniques (UM2), Institut National des Sciences de l'Univers, Centre National de la Recherche Scientifique, Conseil Regional de Bretagne, Commissariat a l'Energie Atomique et aux Energies Alternatives, Centre National d'Etudes Spatiales, Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), and Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)
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[PHYS]Physics [physics] ,Atmospheric Science ,Trimethylamine ,CRESU ,010402 general chemistry ,01 natural sciences ,0104 chemical sciences ,Gas phase ,Chemical kinetics ,chemistry.chemical_compound ,chemistry ,Space and Planetary Science ,Geochemistry and Petrology ,Ab initio quantum chemistry methods ,0103 physical sciences ,Physical chemistry ,Reactivity (chemistry) ,Supersonic speed ,[PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph] ,Molecular physics ,010303 astronomy & astrophysics ,Dimethylamine ,ComputingMilieux_MISCELLANEOUS - Abstract
The gas phase reactivity of the CN radical in the presence of dimethylamine (CH3)2NH and trimethylamine (CH3)3N has been investigated experimentally using a uniform supersonic expansion CRESU react...
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- 2018
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6. Recent advances in collisional effects on spectra of molecular gases and their practical consequences
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Alain Campargue, Franck Thibault, Daniel Lisak, Joseph T. Hodges, R. Armante, Geoffrey C. Toon, Samir Kassi, Jean-Michel Hartmann, Livio Gianfrani, Ha Tran, Sandrine Guerlet, Magnus Gustafsson, Iouli E. Gordon, Christian Boulet, François Forget, Hartmann, Jean-Michel, Tran, Ha, Armante, Raymond, Boulet, Christian, Campargue, Alain, Forget, Françoi, Gianfrani, Livio, Gordon, Iouli, Guerlet, Sandrine, Gustafsson, Magnu, Hodges, Joseph T., Kassi, Samir, Lisak, Daniel, Thibault, Franck, Toon, Geoffrey C., Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences Moléculaires d'Orsay (ISMO), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11), Laboratoire Interdisciplinaire de Physique [Saint Martin d’Hères] (LIPhy), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Università degli studi della Campania 'Luigi Vanvitelli', Luleå University of Technology (LUT), Nicolaus Copernicus University [Toruń], Institut de Physique de Rennes (IPR), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), California Institute of Technology (CALTECH), Knut and Alice Wallenberg Foundation, NASA, NASA grant from AURA program, NASA grant from PDART program, NIST Greenhouse Gas Measurement and Climate Research Program, NASA [NNH15AZ96I], National Science Center, Poland [2015/18/E/ST2/00585], École normale supérieure - Paris (ENS Paris)-École normale supérieure - Paris (ENS Paris), École normale supérieure - Paris (ENS Paris)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Joseph Fourier - Grenoble 1 (UJF), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Università degli studi della Campania 'Luigi Vanvitelli' = University of the Study of Campania Luigi Vanvitelli, and Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS)
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[PHYS]Physics [physics] ,Physics ,Radiation ,010504 meteorology & atmospheric sciences ,Experimental techniques ,Available data ,CRESU ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,Spectral line ,Molecular gases ,Metrology ,Theories and models ,0103 physical sciences ,Atomic and molecular collisions ,Statistical physics ,Quantum dynamics ,Pressure effects on spectral shapes ,Molecular physics ,010306 general physics ,Consequences for applications ,Spectroscopy ,0105 earth and related environmental sciences - Abstract
International audience; We review progress, since publication of the book "Collisional effects on molecular spectra Laboratory experiments and models, consequences for applications" (Elsevier, Amsterdam, 2008), on measuring, modeling and predicting the influence of pressure (ie of intermolecular collisions) on the spectra of gas molecules. We first introduce recently developed experimental techniques of high accuracy and sensitivity. We then complement the aforementioned book by presenting the theoretical approaches, results and data proposed (mostly) in the last decade on the topics of isolated line shapes, line-broadening and-shifting, line-mixing, the far wings and associated continua, and collision-induced absorption. Examples of recently demonstrated consequences of the progress in the description of spectral shapes for some practical applications (metrology, probing of gas media, climate predictions) are then given. Remaining issues and directions for future research are finally discussed.
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- 2018
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7. Low temperature kinetics and theoretical studies of the reaction CN + CH3NH2: a potential source of cyanamide and methyl cyanamide in the interstellar medium
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André Canosa, Dimitrios Skouteris, Chantal Sleiman, Gisèle El Dib, Nadia Balucani, Marzio Rosi, Institut de Physique de Rennes (IPR), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), Università degli Studi di Perugia = University of Perugia (UNIPG), Scuola Normale Superiore di Pisa (SNS), NB, New Balance, CEA, California Earthquake Authority, MIUR, Ministero dell’Istruzione, dell’Università e della Ricerca, Conseil Régional de Bretagne, CNES, Centre National d’Etudes Spatiales, ARC, Auckland Regional Council, 2015F59J3R, CAOS, Chinese American Ophthalmological Society, ERC, European Research Council, Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), Università degli Studi di Perugia (UNIPG), Sleiman, Chantal, El Dib, Gisèle, Rosi, Marzio, Skouteris, Dimitrio, Balucani, Nadia, and Canosa, André
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astrochemistry, ab initio calculations, potential energy surface ,Interstellar cloud ,General Physics and Astronomy ,010402 general chemistry ,Photochemistry ,01 natural sciences ,7. Clean energy ,chemistry.chemical_compound ,0103 physical sciences ,Physical and Theoretical Chemistry ,Laser-induced fluorescence ,010303 astronomy & astrophysics ,[PHYS]Physics [physics] ,astrochemistry ,Chemistry ,Methylamine ,ab initio calculations ,Photodissociation ,CRESU ,0104 chemical sciences ,Interstellar medium ,13. Climate action ,Yield (chemistry) ,Potential energy surface ,Cyanamide ,Molecular physics ,potential energy surface - Abstract
International audience; The reaction between cyano radicals (which are ubiquitous in interstellar clouds) and methylamine (a molecule detected in various interstellar sources) has been investigated in a synergistic experimental and theoretical study. The reaction has been found to be very fast in the entire range of temperatures investigated (23-297 K) by using a CRESU apparatus coupled to pulsed laser photolysis-laser induced fluorescence. The global experimental rate coefficient is given by In addition, dedicated electronic structure calculations of the underlying potential energy surface have been performed, together with capture theory and RRKM calculations. The experimental data have been interpreted in the light of the theoretical calculations and the product branching ratio has been established. According to the present study, in the range of temperatures investigated the title reaction is an efficient interstellar route of formation of cyanamide, NH2CN, another interstellar species. The second most important channel is the one leading to methyl cyanamide, CH3NHCN (an isomer of aminoacetonitrile), via a CN/H exchange mechanism with a yield of 12% of the global reaction in the entire range of temperatures explored. For a possible inclusion in future astrochemical models we suggest, by referring to the usual expression the following values α = 3.68 × 10-12 cm3 molec-1 s-1, β = -1.80, γ = 7.79 K for the channel leading to NH2CN + CH3; α = 5.05 × 10-13 cm3 molec-1 s-1, β = -1.82, γ = 7.93 K for the channel leading to CH3NHCN + H. © 2018 the Owner Societies.
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- 2018
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8. Demonstration of the branching ratio inversion for the electron attachment to phosphoryl chloride POCl3 in the gas phase between 300 and 200 K
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Sophie Carles, Nicholas S. Shuman, Ngary Guen, Jean-Luc Le Garrec, Albert A. Viggiano, James Mitchell, Ghassen Saidani, Institut de Physique de Rennes (IPR), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), Air Force Research Laboratory (AFRL), United States Air Force (USAF), and Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS)
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[PHYS]Physics [physics] ,Exothermic reaction ,Phosphoryl chloride ,Kinetic model ,Chemistry ,Branching fraction ,010401 analytical chemistry ,Analytical chemistry ,General Physics and Astronomy ,Branching ratio ,CRESU ,Atmospheric temperature range ,010402 general chemistry ,Mass spectrometry ,01 natural sciences ,0104 chemical sciences ,Gas phase ,chemistry.chemical_compound ,Electron attachment ,Organic chemistry ,Physical and Theoretical Chemistry ,Molecular physics ,ComputingMilieux_MISCELLANEOUS - Abstract
Electron attachment to phosphoryl chloride (phosphorus oxychloride) POCl 3 has been studied in the gas phase by mass spectrometry at several low temperatures (47.7, 74.5, 169.7 and 199.5 K) with the CRESU method. By measuring over this temperature range and data from [8] , we have demonstrated the inversion of the branching ratio between the exothermic non-dissociative exit channel POCl 3 − and the thermo-neutral dissociative exit channel POCl 2 − + Cl. A kinetic model in terms of statistical theory is used to fit the experimental data.
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- 2016
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9. Pressure dependent low temperature kinetics for CN + CH3CN: competition between chemical reaction and van der Waals complex formation
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Chantal Sleiman, André Canosa, Gisèle El Dib, Sergio González, Stephen J. Klippenstein, Dahbia Talbi, Institut de Physique de Rennes (IPR), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), Universidad de Castilla-La Mancha (UCLM), Chemical Sciences and Engineering Division [Argonne], Argonne National Laboratory [Lemont] (ANL), Laboratoire Univers et Particules de Montpellier (LUPM), Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), PhD fellowship, Conseil Régional de Bretagne, Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), Universidad de Castilla-La Mancha = University of Castilla-La Mancha (UCLM), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), and Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Montpellier 2 - Sciences et Techniques (UM2)
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Work (thermodynamics) ,Interstellar cloud ,Ab initio ,General Physics and Astronomy ,Thermodynamics ,010402 general chemistry ,7. Clean energy ,01 natural sciences ,Chemical reaction ,symbols.namesake ,Transition state theory ,0103 physical sciences ,Physical and Theoretical Chemistry ,010303 astronomy & astrophysics ,[PHYS]Physics [physics] ,Chemistry ,Anharmonicity ,CRESU ,0104 chemical sciences ,Theorem of corresponding states ,[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry ,13. Climate action ,symbols ,Physical chemistry ,van der Waals force ,Molecular physics - Abstract
International audience; The gas phase reaction between the CN radical and acetonitrile CH3CN was investigated experimentally, at low temperatures, with the CRESU apparatus and a slow flow reactor to explore the temperature dependence of its rate coefficient from 354 K down to 23 K. Whereas a standard Arrhenius behavior was found at T > 200 K, indicating the presence of an activation barrier, a dramatic increase in the rate coefficient by a factor of 130 was observed when the temperature was decreased from 168 to 123 K. The reaction was found to be pressure independent at 297 K unlike the experiments carried out at 52 and 132 K. The work was complemented by ab initio transition state theory based master equation calculations using reaction pathways investigated with highly accurate thermochemical protocols. The role of collisional stabilization of a CN⋯CH3CN van der Waals complex and of tunneling induced H atom abstractions were also considered. The experimental pressure dependence at 52 and 132 K is well reproduced by the theoretical calculations provided that an anharmonic state density is considered for the van der Waals complex CH3CN⋯CN and its Lennard-Jones radius is adjusted. Furthermore, these calculations indicate that the experimental observations correspond to the fall-off regime and that tunneling remains small in the low-pressure regime. Hence, the studied reaction is essentially an association process at very low temperature. Implications for the chemistry of interstellar clouds and Titan are discussed.
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- 2016
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10. Development of a pulsed uniform supersonic gas expansion system based on an aerodynamic chopper for gas phase reaction kinetic studies at ultra-low temperatures
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José Albaladejo, Bernabé Ballesteros, T.M. Townsend, F. J. Maigler, André Canosa, Elena Jiménez, V. Napal, Bertrand R. Rowe, Institut de Physique de Rennes (IPR), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), CSD2009-00038, Spanish Ministry of Science and Innovation, PEII-2014-043-P, Junta de Comindades de Castilla-La Mancha, CGL2013-43227-R, Spanish Ministry of Economy and Competitiveness, Université de Rennes 1 (UR1), and Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS)
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[PHYS]Physics [physics] ,Jet (fluid) ,Materials science ,Nozzle ,chemistry.chemical_element ,Aerodynamics ,CRESU ,Laser ,7. Clean energy ,law.invention ,Nuclear magnetic resonance ,chemistry ,law ,[SDU]Sciences of the Universe [physics] ,[CHIM]Chemical Sciences ,Supersonic speed ,Atomic physics ,Laser-induced fluorescence ,Molecular physics ,Instrumentation ,Choked flow ,Helium - Abstract
International audience; A detailed description of a new pulsed supersonic uniform gas expansion system is presented together with the experimental validation of the setup by applying the CRESU (French acronym for Cinétique de Réaction en Ecoulement Supersonique Uniforme or Reaction Kinetics in a Uniform Supersonic Flow ) technique to the gas-phase reaction of OH radicals with 1-butene at ca. 23 K and 0.63 millibars of helium (carrier gas). The carrier gas flow, containing negligible mixing ratios of OH-precursor and 1-butene, is expanded from a high pressure reservoir (337 millibars) to a low pressure region (0.63 millibars) through a convergent-divergent nozzle (Laval type). The novelty of this experimental setup is that the uniform supersonic flow is pulsed by means of a Teflon-coated aerodynamic chopper provided with two symmetrical apertures. Under these operational conditions, the designed Laval nozzle achieves a temperature of (22.4 ± 1.4) K in the gas jet. The spatial characterization of the temperature and the total gas density within the pulsed uniform supersonic flow has also been performed by both aerodynamical and spectroscopic methods. The gas consumption with this technique is considerably reduced with respect to a continuous CRESU system. The kinetics of the OH+1-butene reaction was investigated by the pulsed laser photolysis/laser induced fluorescence technique. The rotation speed of the disk is temporally synchronized with the exit of the photolysis and the probe lasers. The rate coefficient (k OH) for the reaction under investigation was then obtained and compared with the only available data at this temperature.
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- 2015
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11. Corrigendum to 'Low temperature (39–298 K) kinetics study of the reactions of the C4H radical with various hydrocarbons observed in Titan’s atmosphere' [Icarus 194 (2008) 746–757]
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Marie-Claire Gazeau, Petre Birza, Ian R. Sims, André Canosa, Coralie Berteloite, Sébastien D. Le Picard, Yves Bénilan, Institut de Physique de Rennes (IPR), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA (UMR_7583)), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), and Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS)
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[PHYS]Physics [physics] ,ICARUS ,Materials science ,010504 meteorology & atmospheric sciences ,Kinetics ,Astronomy and Astrophysics ,CRESU ,Atmospheric sciences ,01 natural sciences ,7. Clean energy ,[PHYS.PHYS.PHYS-GEN-PH]Physics [physics]/Physics [physics]/General Physics [physics.gen-ph] ,Astrobiology ,symbols.namesake ,13. Climate action ,Space and Planetary Science ,0103 physical sciences ,symbols ,Molecular physics ,Titan (rocket family) ,010303 astronomy & astrophysics ,ComputingMilieux_MISCELLANEOUS ,0105 earth and related environmental sciences - Abstract
International audience; no abstract
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- 2011
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12. Laboratory measurements of the recombination of PAH ions with electrons: implications for the PAH charge state in interstellar clouds
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Bertrand R. Rowe, Oldrich Novotny, Anne Foutel-Richard, C. Rebrion-Rowe, Sophie Carles, Ludovic Biennier, Mohamed Alsayed-Ali, Physique des atomes, lasers, molécules et surfaces (PALMS), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), Masaryk University [Brno] (MUNI), Institut de Physique de Rennes (IPR), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), and Department of Neurology, Faculty Hospital and Masaryk University Brno
- Subjects
[PHYS]Physics [physics] ,010304 chemical physics ,Chemistry ,Interstellar cloud ,Acenaphthene ,Electron ,CRESU ,Azulene ,01 natural sciences ,Afterglow ,Ion ,Interstellar medium ,chemistry.chemical_compound ,13. Climate action ,Chemical physics ,0103 physical sciences ,[SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology ,Physical and Theoretical Chemistry ,Atomic physics ,Molecular physics ,010303 astronomy & astrophysics ,Recombination - Abstract
International audience; Laboratory measurements of the recombination of polycyclic aromatic hydrocarbon (PAH) ions with electrons are presented. Experimental data have been obtained at room temperature for azulene (C10H8) and acenaphthene (C12H10) cations by the Flowing Afterglow with PhotoIons method. The results confirm that the recombination of PAH ions is fast although well below the geometrical limit. The set of our recent and present measurements reveal a definite trend of increasing rate with the number of carbon atoms of the PAH. This behaviour that needs further characterization is potentially of great interest for charge state models as recombination is a dominant mechanism of PAH ion destruction in the interstellar medium. The design of experiments to measure the recombination of larger PAHs and their temperature dependence is discussed.
- Published
- 2006
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