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286 results on '"D M, Cullen"'

6. Decay spectroscopy of Os171,172 and Ir171,172,174

Author

W. Zhang, B. Cederwall, M. Doncel, Ö. Aktas, A. Ertoprak, C. Qi, T. Grahn, B. S. Nara Singh, D. M. Cullen, D. Hodge, M. Giles, S. Stolze, K. Auranen, H. Badran, T. Braunroth, T. Calverley, D. M. Cox, Y. D. Fang, P. T. Greenlees, J. Hilton, E. Ideguchi, R. Julin, S. Juutinen, M. Kumar Raju, M. Leino, H. Li, H. Liu, S. Matta, P. Subramaniam, V. Modamio, J. Pakarinen, P. Papadakis, J. Partanen, C. M. Petrache, P. Rahkila, P. Ruotsalainen, M. Sandzelius, J. Sarén, C. Scholey, J. Sorri, M. J. Taylor, J. Uusitalo, and J. J. Valiente-Dobón

Published
2023

9. Evidence of Partial Seniority Conservation in the πg_{9/2} Shell for the N=50 Isotones

Author

R M, Pérez-Vidal, A, Gadea, C, Domingo-Pardo, A, Gargano, J J, Valiente-Dobón, E, Clément, A, Lemasson, L, Coraggio, M, Siciliano, S, Szilner, M, Bast, T, Braunroth, J, Collado, A, Corina, A, Dewald, M, Doncel, J, Dudouet, G, de France, C, Fransen, V, González, T, Hüyük, B, Jacquot, P R, John, A, Jungclaus, Y H, Kim, A, Korichi, M, Labiche, S, Lenzi, H, Li, J, Ljungvall, A, López-Martens, D, Mengoni, C, Michelagnoli, C, Müller-Gatermann, D R, Napoli, A, Navin, B, Quintana, D, Ramos, M, Rejmund, E, Sanchis, J, Simpson, O, Stezowski, D, Wilmsen, M, Zielińska, A J, Boston, D, Barrientos, P, Bednarczyk, G, Benzoni, B, Birkenbach, H C, Boston, A, Bracco, B, Cederwall, D M, Cullen, F, Didierjean, J, Eberth, A, Gottardo, J, Goupil, L J, Harkness-Brennan, H, Hess, D S, Judson, A, Kaşkaş, W, Korten, S, Leoni, R, Menegazzo, B, Million, J, Nyberg, Zs, Podolyak, A, Pullia, D, Ralet, F, Recchia, P, Reiter, K, Rezynkina, M D, Salsac, M, Şenyiğit, D, Sohler, Ch, Theisen, D, Verney, Ministerio de Ciencia e Innovación (España), Generalitat Valenciana, European Commission, Department of Energy (US), Croatian Science Foundation, and Pérez-Vidal, R.M.

Abstract

7 pags., 3 figs., 1 tab., The reduced transition probabilities for the 4_{1}^{+}→2_{1}^{+} and 2_{1}^{+}→0_{1}^{+} transitions in ^{92}Mo and ^{94}Ru and for the 4_{1}^{+}→2_{1}^{+} and 6_{1}^{+}→4_{1}^{+} transitions in ^{90}Zr have been determined in this experiment making use of a multinucleon transfer reaction. These results have been interpreted on the basis of realistic shell-model calculations in the f_{5/2}, p_{3/2}, p_{1/2}, and g_{9/2} proton valence space. Only the combination of extensive lifetime information and large scale shell-model calculations allowed the extent of the seniority conservation in the N=50 g_{9/2} orbital to be understood. The conclusion is that seniority is largely conserved in the first πg_{9/2} orbital., This work was partially supported by MCIN/AEI/10.13039/501100011033 and Generalitat Valenciana, Spain, under Grants No. FPA2017-84756-C4, No. PID2020–118265GB-C4, and No. PROMETEO 2019/005, by the EU FEDER funds, by the European Union’s Horizon 2020 research and innovation program under Grant Agreement No. n654002, by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics, under Contract No. DE-AC02-06CH11357, by STFC(UK) and by the Croatian Science Foundation under Projects No. 7194 and No. IP-2018-01-1257.

Published
2022

10. Evidence of Partial Seniority Conservation in the πg9/2 Shell for the N=50 Isotones

Author

R. M. Pérez-Vidal, A. Gadea, C. Domingo-Pardo, A. Gargano, J. J. Valiente-Dobón, E. Clément, A. Lemasson, L. Coraggio, M. Siciliano, S. Szilner, M. Bast, T. Braunroth, J. Collado, A. Corina, A. Dewald, M. Doncel, J. Dudouet, G. de France, C. Fransen, V. González, T. Hüyük, B. Jacquot, P. R. John, A. Jungclaus, Y. H. Kim, A. Korichi, M. Labiche, S. Lenzi, H. Li, J. Ljungvall, A. López-Martens, D. Mengoni, C. Michelagnoli, C. Müller-Gatermann, D. R. Napoli, A. Navin, B. Quintana, D. Ramos, M. Rejmund, E. Sanchis, J. Simpson, O. Stezowski, D. Wilmsen, M. Zielińska, A. J. Boston, D. Barrientos, P. Bednarczyk, G. Benzoni, B. Birkenbach, H. C. Boston, A. Bracco, B. Cederwall, D. M. Cullen, F. Didierjean, J. Eberth, A. Gottardo, J. Goupil, L. J. Harkness-Brennan, H. Hess, D. S. Judson, A. Kaşkaş, W. Korten, S. Leoni, R. Menegazzo, B. Million, J. Nyberg, Zs. Podolyak, A. Pullia, D. Ralet, F. Recchia, P. Reiter, K. Rezynkina, M. D. Salsac, M. Şenyiğit, D. Sohler, Ch. Theisen, and D. Verney

Subjects
General Physics and Astronomy
Published
2022

11. Multi-scale characterization and simulation of impact welding between immiscible Mg/steel alloys

Author

D. M. Cullen, Xin Sun, Glenn S. Daehn, Anupam Vivek, Jiahao Cheng, and Xiaohua Hu

Subjects
Materials science, Polymers and Plastics, Scanning electron microscope, Mechanical Engineering, Metals and Alloys, Intermetallic, 02 engineering and technology, Welding, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, Nanocrystalline material, 0104 chemical sciences, law.invention, Mechanics of Materials, law, Materials Chemistry, Ceramics and Composites, Composite material, Deformation (engineering), Magnesium alloy, 0210 nano-technology, High-resolution transmission electron microscopy, Spot welding
Abstract

Vaporizing foil actuator spot welding method is used in this paper to join magnesium alloy AZ31 and uncoated high-strength steel DP590, which are typically considered as un-weldable due to their high physical property disparities, low mutual solubility, and the lack of any intermetallic phases. Characterization results from scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM) of the weld interface indicate that the impact creates an Mg nanocrystalline interlayer with abundant Fe particles. The interlayer exhibits intact bonding with both DP590 and AZ31 substrates. To investigate the fundamental bond formation mechanisms at the interface, a finite element (FE)-based process simulation is first performed to calculate the local temperature and deformation at the interface under the given macroscopic experimental condition. Taking the FE results at the interface as inputs, molecular dynamics (MD) simulations are conducted to study the interlayer formation at the Mg/Fe interface during the impact and cooling. The results found a high velocity shearing-induced mechanical mixing mechanism that mixes Mg/Fe atoms at the interface and creates the interlayer, leading to the metallurgical bond between Mg/steel alloys.

Published
2020

15. Evidence for spherical-oblate shape coexistence in Tc-87

Author

X. Liu, B. Cederwall, C. Qi, R. A. Wyss, Ö. Aktas, A. Ertoprak, W. Zhang, E. Clément, G. de France, D. Ralet, A. Gadea, A. Goasduff, G. Jaworski, I. Kuti, B. M. Nyakó, J. Nyberg, M. Palacz, R. Wadsworth, J. J. Valiente-Dobón, H. Al-Azri, A. Ataç Nyberg, T. Bäck, G. de Angelis, M. Doncel, J. Dudouet, A. Gottardo, M. Jurado, J. Ljungvall, D. Mengoni, D. R. Napoli, C. M. Petrache, D. Sohler, J. Timár, D. Barrientos, P. Bednarczyk, G. Benzoni, B. Birkenbach, A. J. Boston, H. C. Boston, I. Burrows, L. Charles, M. Ciemala, F. C. L. Crespi, D. M. Cullen, P. Désesquelles, C. Domingo-Pardo, J. Eberth, N. Erduran, S. Ertürk, V. González, J. Goupil, H. Hess, T. Huyuk, A. Jungclaus, W. Korten, A. Lemasson, S. Leoni, A. Maj, R. Menegazzo, B. Million, R. M. Perez-Vidal, Zs. Podolyàk, A. Pullia, F. Recchia, P. Reiter, F. Saillant, M. D. Salsac, E. Sanchis, J. Simpson, O. Stezowski, C. Theisen, M. Zielińska, Swedish Research Council, Science and Technology Facilities Council (UK), National Science Centre (Poland), National Research, Development and Innovation Office (Hungary), Ministerio de Ciencia e Innovación (España), Generalitat Valenciana, China Scholarship Council, and Liu, X.

Subjects
Subatomär fysik, Atom and Molecular Physics and Optics, Subatomic Physics, Atom- och molekylfysik och optik
Abstract

6 pags., 8 figs., 1 tab., Excited states in the neutron-deficient nucleus Tc87 have been studied via the fusion-evaporation reaction Fe54(Ar36,2n1p)Tc87 at 115 MeV beam energy. The AGATA γ-ray spectrometer coupled to the DIAMANT, NEDA, and Neutron Wall detector arrays for light-particle detection was used to measure the prompt coincidence of γ rays and light particles. Six transitions from the deexcitation of excited states belonging to a new band in Tc87 were identified by comparing γ-ray intensities in the spectra gated under different reaction channel selection conditions. The constructed level structure was compared with the shell model and total Routhian surface calculations. The results indicate that the new band structure in Tc87 is built on a spherical configuration, which is different from that assigned to the previously identified oblate yrast rotational band., This work was supported by the Swedish Research Council under Grants No. 621-2014-5558 and No. 2019-04880; the EU 7th Framework Programme, Integrating Activities Transnational Access, Project No. 262010 ENSAR; the UK STFC under Grants No. ST/L005727/1 and No. ST/P003885/1; the Polish National Science Centre, Grants No. 2016/22/M/ST2/00269 and No. 2017/25/B/ST2/01569; COPIN-INFN, COPIN-IN2P3, and COPIGAL projects; the National Research, Development and Innovation Fund of Hungary (Project No. K128947); the European Regional Development Fund (Contract No. GINOP-2.3.3-15-2016-00034); the Hungarian National Research, Development and Innovation Office, NKFIH, Contract No. PD124717; the Ministerio de Ciencia e Innovación and Generalitat Valenciana, Spain, under the Grants No. SEV-2014-0398 and No. FPA2017-84756-C4; PROMETEO/2019/005; and by the EU FEDER funds. X.L. gratefully acknowledges support from the China Scholarship Council, Grant No. 201700260183, for his stay in Sweden. We acknowledge the support from the AGATA Collaboration and thank the GANIL staff for excellent technical support and operation

Published
2022

16. Identification of excited states in Te5552107

Author

W. Zhang, B. Cederwall, C. Qi, A. Ertoprak, Ö. Aktas, X. Liu, K. Andgren, K. Auranen, T. Bäck, L. Barber, G. Beeton, D. M. Cullen, I. G. Darby, M. R. Dimmock, S. Eeckhaudt, E. Ganioğlu, M. Górska, T. Grahn, P. T. Greenlees, B. Hadinia, E. Ideguchi, A. Illana, P. M. Jones, D. T. Joss, R. Julin, S. Juutinen, J. M. Keatings, A. Khaplanov, F. Kulali, M. Leino, M. Luoma, B. Lv, B. S. Nara Singh, L. Nelson, M. Niikura, M. Nyman, J. Ojala, R. D. Page, J. Pakarinen, E. S. Paul, C. Petrache, M. Petri, P. Rahkila, P. Ruotsalainen, M. Sandzelius, J. Sarén, C. Scholey, J. F. Smith, J. Sorri, H. Tann, G. Zimba, J. Uusitalo, R. Wadsworth, and R. Wyss

Subjects
010308 nuclear & particles physics, 0103 physical sciences, 010306 general physics, 01 natural sciences
Published
2021

17. Reinterpretation of excited states in Po212 : Shell-model multiplets rather than α -cluster states

Author

B. Million, E. Dupont, Bertrand Jacquot, R. Menegazzo, M. Ciemala, M. Zielińska, R. M. Perez-Vidal, L. J. Harkness-Brennan, D. Mengoni, Vicente González, W. Korten, D. Kocheva, D. Ralet, D. R. Napoli, P. Reiter, J. Eberth, Zs. Podolyák, A. Astier, B. Birkenbach, C. Michelagnoli, G. Tocabens, A. Perea, J. Dudouet, Ch. Lorenz, A. Bracco, A. Maj, M. Jurado, Begoña Quintana, A. Fernández, H. C. Boston, J. Ropert, J. Ljungvall, L. Ménager, Dirk Rudolph, G. Benzoni, H. Naïdja, E. Nácher, A. Korichi, A. Jungclaus, K. Wimmer, J. J. Valiente-Dobón, C. Houarner, A. Gadea, Johan Nyberg, J. Collado, A. Pullia, A. Gargano, Hans-Jurgen E. Hess, A. J. Boston, Emyr Clement, J. Goupil, A. Såmark-Roth, Enrique Sanchis, Diego Barrientos, S. Leoni, G. Frémont, N. Lalović, F. Saillant, D. S. Judson, O. Stezowski, A. Lemasson, C. Spitaels, S. Ansari, G. S. Simpson, D. M. Cullen, A. Illana, N. Redon, Luis Sarmiento, C. M. Petrache, G. Rainovski, Ch. Theisen, H. J. Li, C. Domingo-Pardo, and Pavel Golubev

Subjects
Reinterpretation, Physics, 010308 nuclear & particles physics, Excited state, 0103 physical sciences, SHELL model, Cluster (physics), Atomic physics, 010306 general physics, 01 natural sciences
Published
2021

18. Erratum: Probing isospin symmetry in the (Fe50,Mn50,Cr50) isobaric triplet via electromagnetic transition rates [Phys. Rev. C 99 , 044317 (2019)]

Author

D. Wölk, C. Fransen, B. S. Nara Singh, C. Müller-Gatermann, F. Mammes, A. Blazhev, M. J. Mallaburn, Alfredo Poves, M. M. Giles, S. M. Lenzi, A. Dewald, K. O. Zell, L. Barber, D. M. Cullen, A. Goldkuhle, J. Jolie, Thomas Braunroth, and M. Beckers

Subjects
Physics, Isospin, Isobaric process, Atomic physics, Symmetry (physics)
Published
2021

19. Evidence for enhanced neutron-proton correlations from the level structure of the N=Z+1 nucleus Tc444387

Author

X. Liu, B. Cederwall, C. Qi, R. A. Wyss, Ö. Aktas, A. Ertoprak, W. Zhang, E. Clément, G. de France, D. Ralet, A. Gadea, A. Goasduff, G. Jaworski, I. Kuti, B. M. Nyakó, J. Nyberg, M. Palacz, R. Wadsworth, J. J. Valiente-Dobón, H. Al-Azri, A. Ataç Nyberg, T. Bäck, G. de Angelis, M. Doncel, J. Dudouet, A. Gottardo, M. Jurado, J. Ljungvall, D. Mengoni, D. R. Napoli, C. M. Petrache, D. Sohler, J. Timár, D. Barrientos, P. Bednarczyk, G. Benzoni, B. Birkenbach, A. J. Boston, H. C. Boston, I. Burrows, L. Charles, M. Ciemala, F. C. L. Crespi, D. M. Cullen, P. Désesquelles, C. Domingo-Pardo, J. Eberth, N. Erduran, S. Ertürk, V. González, J. Goupil, H. Hess, T. Huyuk, A. Jungclaus, W. Korten, A. Lemasson, S. Leoni, A. Maj, R. Menegazzo, B. Million, R. M. Perez-Vidal, Zs. Podolyàk, A. Pullia, F. Recchia, P. Reiter, F. Saillant, M. D. Salsac, E. Sanchis, J. Simpson, O. Stezowski, C. Theisen, and M. Zielińska

Subjects
Physics, Proton, Spectrometer, 010308 nuclear & particles physics, Isoscalar, Nuclear Theory, 01 natural sciences, Charged particle, Excited state, 0103 physical sciences, Level structure, Neutron, AGATA, Atomic physics, Nuclear Experiment, 010306 general physics
Abstract

The low-lying excited states in the neutron-deficient $N = Z + 1$ nucleus $^{87}_{43}$Tc$_{44}$ have been studied via the fusion-evaporation reaction $^{54}$Fe $(^{36}Ar, 2n1p)$ $^{87}$Tc at the Grand Accelerateur National d'Ions Lourds (GANIL), France. The AGATA spectrometer was used in conjunction with the auxiliary NEDA, Neutron Wall, and DIAMANT detector arrays to measure coincident prompt γ rays, neutrons, and charged particles emitted in the reaction. A level scheme of $^{87}$Tc from the $(9/2^+_{g.s})$ state to the $( 33 / 2^+_1$) state was established based on six mutually coincident γ -ray transitions. The constructed level structure exhibits a rotational behavior with a sharp backbending at $ℏω ≈ 0.50$ MeV. A decrease in alignment frequency and increase in alignment sharpness in the odd-mass isotonic chains around $N=44$ is proposed as an effect of the enhanced isoscalar neutron-proton interactions in odd-mass nuclei when approaching the $N=Z$ line.

Published
2021

20. AST Development for PEM Electrolyzers

Author

Siddharth Komini Babu, Xiaoxiao Qiao, Christopher Evan Van Pelt, Deborah J. Myers, Abdurrahman Yilmaz, Jacob S. Spendelow, Rangachary Mukundan, D. M. Cullen, and Tanya Agarwal

Subjects
Engineering, business.industry, Process engineering, business
Published
2021

22. A time-of-flight correction procedure for fast-timing data of recoils with varying implantation positions at a spectrometer focal plane

Author

L. Barber, M. Smolen, Joonas Konki, J. F. Smith, M. M. Giles, Mikael Sandzelius, C. Scholey, Michael Taylor, B. S. Nara Singh, Rauno Julin, Panu Rahkila, E.R. Gamba, Paul Greenlees, S. Lalkovski, R. Mărginean, F. Bisso, Jan Sarén, O. Neuvonen, Kalle Auranen, Zs. Podolyák, Philippos Papadakis, C. R. Nobs, H. Badran, P. H. Regan, N. Marginean, M. J. Mallaburn, Jari Partanen, Janne Pakarinen, C. Mihai, A. Herzáň, Alison Bruce, D. M. Cullen, A. Lightfoot, D. Hodge, Juha Sorri, C. R. Niţă, Sanna Stolze, Tuomas Grahn, Juha Uusitalo, Daniel Cox, and R. E. Mihai

Subjects
Nuclear and High Energy Physics, Photon, Generalised-centroid-difference method, tutkimuslaitteet, spektrometrit, Standard deviation, 138Gd, Recoil, generalised-centroid-difference method, Distributed source, Nuclear Experiment, Nuclear-state lifetimes, Instrumentation, detectors, Physics, nuclear-state lifetimes, ta114, Spectrometer, fast-timing, Detector, Centroid, Fast-timing, LaBr3, Computational physics, Time of flight, Cardinal point, distributed source, ydinfysiikka
Abstract

Fast-timing measurements at the focal plane of a separator can suffer from poor timing resolution. This is due to the variations in time-of-flight (ToF) for photons travelling to a given detector, which arise from the changes in the implantation positions of the recoil nuclei emitting the γ rays of interest. In order to minimise these effects on timing measurements, a procedure is presented that improves fast-timing data by performing ToF corrections on an event-by-event basis. This method was used to correct data collected with an array of eight LaBr 3 detectors, which detected γ rays from spatially distributed 138Gd recoil-implants at the focal plane of the Recoil-Ion-Transport-Unit (RITU) spectrometer. The Generalised Centroid Difference (GCD) method was used to extract a lifetime from data in conjunction with a new procedure to calibrate the time walk. The lifetime of the first 2 + state in 138Gd, populated by the decay of the K π = 8 − isomeric state, was measured to be 229(24) ps using the ToF-corrected data, which is consistent within three standard deviations to the literature value. The results together with Monte-Carlo simulations show that the ToF correction procedure reduced the uncertainty in the measured lifetimes by 3 % in the case of the spatially distributed nuclei at the focal plane of RITU. However, ∼ 12 % has been estimated for a similar experiment when using a larger focal plane i.e. the Super-FRS at the FAIR facility.

Published
2019

23. Mass-transport properties of electrosprayed Pt/C catalyst layers for polymer-electrolyte fuel cells

Author

Ahmet Kusoglu, Adam Z. Weber, Anamika Chowdhury, Julio J. Conde, Paloma Ferreira-Aparicio, Antonio M. Chaparro, M. Antonia Folgado, and D. M. Cullen

Subjects
Materials science, Renewable Energy, Sustainability and the Environment, Energy Engineering and Power Technology, Proton exchange membrane fuel cell, chemistry.chemical_element, 02 engineering and technology, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, 0104 chemical sciences, Dielectric spectroscopy, Catalysis, chemistry.chemical_compound, chemistry, Chemical engineering, Nafion, Ionic conductivity, Electrical and Electronic Engineering, Physical and Theoretical Chemistry, 0210 nano-technology, Platinum, Polarization (electrochemistry), Ionomer
Abstract

Mass-transport properties of electrosprayed catalyst-layers based on Pt/C and ionomer (Nafion) are studied with hydrogen limiting-current technique, water-vapor-uptake, scanning transmission microscopy (STEM), single-cell testing, and impedance spectroscopy. The hydrogen limiting-current technique provides the transport resistance of the layers (RCLmt), which shows to be lower in electrosprayed layers compared with conventional layers, especially at very low platinum loadings (0.025 mgPt·cm−2) and low cell temperature, denoting superior mass-transport properties. Images of the distribution of Pt, F, and C elements reveal the ionomer preferentially interacting with the Pt nanoparticles. Water-vapor-uptake experiments show larger vapor absorption for electrosprayed than conventional catalyst layers. Such large water-vapor uptake capability is combined with superhydrophobicity, ie. very low interaction with water in liquid phase (wettability). Both apparently contradictory properties result from a particular configuration of the amphiphilic ionomer in the electrosprayed layers, and provide ideal conditions for high mass transport and ionic conductivity in a catalyst layer. Electrosprayed layers as cathode catalyst layers show peak response at a loading of 0.17 mgPt·cm−2 (18 μm layer thickness when using Pt/C 20 wt% catalyst) where they provide minimal mass-transport and polarization resistances.

Published
2019

24. Positional dependence of activity determination in single photon emission computed tomography

Author

Nick Calvert, B Pietras, Emma Page, Jill Tipping, D. M. Cullen, Emlyn Price, A P Robinson, David Hamilton, and Sophia Pells

Subjects
Radionuclide imaging, Single photon emission computed tomography, Monte Carlo method, Physics::Medical Physics, Image processing, Single-photon emission computed tomography, Imaging phantom, 030218 nuclear medicine & medical imaging, 03 medical and health sciences, 0302 clinical medicine, Optics, Calibration, medicine, Technical Note, Image Processing, Computer-Assisted, Dosimetry, Scattering, Radiation, Radiology, Nuclear Medicine and imaging, radionuclide imaging, single photon emission computed tomography computed tomography, Physics, Tomography, Emission-Computed, Single-Photon, medicine.diagnostic_test, business.industry, computed tomography, General Medicine, molecular radiotherapy, Radiology Nuclear Medicine and imaging, quantitative imaging, 030220 oncology & carcinogenesis, Tomography, business, Correction for attenuation
Abstract

Accurate image quantification requires accurate calibration of the detector and is vital if dosimetry is to be performed in molecular radiotherapy. A dependence on the position of calibration has been observed in single photon emission computed tomography images when attenuation correction (AC) and scatter correction are applied. This work investigates the origin of this dependence in single photon emission computed tomography scans of phantom inserts filled with Lu solution. A 113 ml sphere and inserts representing a mathematical model of a spleen and an anatomical model of a patient spleen were imaged at the centre and edge of elliptical phantoms. For these inserts, the difference in calibration factor between the positions was around 10% for images reconstructed with AC and triple energy window scatter correction. A combination of experimental imaging and Monte Carlo simulation was used to isolate possible causes due to imaging or reconstruction in turn. Inconsistent application of AC between different reconstruction systems was identified as the origin of the positional dependence.

Published
2019

25. Nanofiber Fuel Cell MEAs with a PtCo/C Cathode

Author

John Slack, Peter N. Pintauro, D. M. Cullen, Brian T. Sneed, Javier Parrondo, Cenk Gumeci, Natalia Macauley, Karren L. More, R. Mukundan, and Nilesh Dale

Subjects
Materials science, Chemical engineering, Renewable Energy, Sustainability and the Environment, law, Nanofiber, Materials Chemistry, Electrochemistry, Fuel cells, Condensed Matter Physics, Cathode, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, law.invention
Published
2019

26. Atomic-level active sites of efficient imidazolate framework-derived nickel catalysts for CO2 reduction

Author

Hanguang Zhang, Gang Wu, Ying Li, D. M. Cullen, Karren L. More, Guofeng Wang, Zhenyu Liu, Kexi Liu, and Fuping Pan

Subjects
Renewable Energy, Sustainability and the Environment, Chemistry, chemistry.chemical_element, 02 engineering and technology, General Chemistry, Overpotential, 021001 nanoscience & nanotechnology, Photochemistry, Redox, Dissociation (chemistry), Catalysis, Nickel, chemistry.chemical_compound, Imidazolate, General Materials Science, Density functional theory, 0210 nano-technology, Zeolitic imidazolate framework
Abstract

Nickel and nitrogen co-doped carbon (Ni–N–C) has emerged as a promising catalyst for the CO2 reduction reaction (CO2RR); however, the chemical nature of its active sites has remained elusive. Herein, we report the exploration of the reactivity and active sites of Ni–N–C for the CO2RR. Single atom Ni coordinated with N confined in a carbon matrix was prepared through thermal activation of chemically Ni-doped zeolitic imidazolate frameworks (ZIFs) and directly visualized by aberration-corrected scanning transmission electron microscopy. Electrochemical results show the enhanced intrinsic reactivity and selectivity of Ni–N sites for the reduction of CO2 to CO, delivering a maximum CO faradaic efficiency of 96% at a low overpotential of 570 mV. Density functional theory (DFT) calculations predict that the edge-located Ni–N2+2 sites with dangling bond-containing carbon atoms are the active sites facilitating the dissociation of the C–O bond of the *COOH intermediate, while bulk-hosted Ni–N4 is kinetically inactive. Furthermore, the high capability of edge-located Ni–N4 being able to thermodynamically suppress the competitive hydrogen evolution is also explained. The proposal of edge-hosed Ni–N2+2 sites provides new insight into designing high-efficiency Ni–N–C for CO2 reduction.

Published
2019

27. Lifetime measurements of yrast states in $$^{\mathbf {178}}$$Pt using the charge plunger method with a recoil separator

Author

T. Grahn, A. Illana, D. M. Cullen, P. Spagnoletti, B. S. Nara Singh, J. M. Keatings, David O'Donnell, J. Sorri, A. Dewald, J. Ojala, C. Müller-Gatermann, Janne Pakarinen, G. Zimba, Panu Ruotsalainen, P. Rahkila, R.-D. Herzberg, J. Heery, Jan Sarén, L. Barber, Mikael Sandzelius, M. Bowry, J. Vilhena, Matti Leino, J. F. Smith, J. Sinclair, G. Beeton, H. Tann, R. Julin, S. Juutinen, Paul Greenlees, Juha Uusitalo, and M. Luoma

Subjects
Physics, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Yrast, Hadron, Electron, 01 natural sciences, Excited state, 0103 physical sciences, Quadrupole, Alpha decay, Atomic physics, 010306 general physics, Radioactive decay, Lepton
Abstract

Lifetime measurements in $$^{178}$$ 178 Pt with excited states de-exciting through $$\gamma $$ γ -ray transitions and internal electron conversions have been performed. Ionic charges were selected by the in-flight mass separator MARA and measured at the focal plane in coincidence with the $$4_1^+\rightarrow 2_1^+$$ 4 1 + → 2 1 + $$257\,$$ 257 keV $$\gamma $$ γ -ray transition detected using the JUROGAM 3 spectrometer. The resulting charge-state distributions were analysed using the differential decay curve method (DDCM) framework to obtain a lifetime value of 430(20) ps for the $$2_1^+$$ 2 1 + state. This work builds on a method that combines the charge plunger technique with the DDCM analysis. As an alternative analysis, ions were selected in coincidence with the $$^{178}$$ 178 Pt alpha decay ($$E_{\mathrm {alpha}} = 5.458(5)$$ E alpha = 5.458 ( 5 ) MeV) at the focal plane. Lifetime information was obtained by fitting a two-state Bateman equation to the decay curve with the lifetime of individual states defined by a single quadrupole moment. This yielded a lifetime value of 430(50) ps for the $$2_1^+$$ 2 1 + state, and 54(6) ps for the $$4_1^+$$ 4 1 + state. An analysis method based around the Bateman equation will become especially important when using the charge plunger method for the cases where utilising coincidences between prompt $$\gamma $$ γ rays and recoils is not feasible.

Published
2021

29. Excited states in Ra217 populated in the α decay of Th221

Author

M. Siciliano, S. Juutinen, Joonas Konki, C. Scholey, J. F. Smith, Panu Ruotsalainen, D. Hodge, R. Julin, Juha Sorri, Juha Uusitalo, D. Mengoni, Mikael Sandzelius, M. Smolen, R.-D. Herzberg, Ulrika Jakobsson, Marcus Scheck, Sanna Stolze, E. Parr, Philippos Papadakis, Pauli Peura, K. Mulholland, Paul Greenlees, Jan Sarén, T. Grahn, A. Herzáň, D. M. Cullen, Matthew J. Taylor, C. McPeake, Kalle Auranen, P. Rahkila, G. G. O'Neill, Robert Chapman, A. K. Mistry, Jari Partanen, Janne Pakarinen, and L. Grocutt

Subjects
Physics, 010308 nuclear & particles physics, Excited state, 0103 physical sciences, Atomic physics, 010306 general physics, Spectroscopy, 01 natural sciences, Spherical shell
Abstract

Fine structure in the α decay of Th90221, populating excited states in Ra88217, was studied using αγ-coincidence spectroscopy. Two α-decay branches from Th221 have been newly observed, with Eα(keV)[bα(%)]=7951(8)[0.14(3)] and 8247(3)[1.51(12)], together with three previously known branches. Also, two new states in Ra217 were identified at E = 177 and 227 keV. The ground-state configurations of the odd-A, N = 131 transitional isotones above Pb208 are interpreted from their α-decay fine structure systematics and considered in terms of predictions using spherical shell and reflection-asymmetric models.

Published
2020

30. γ -ray spectroscopy of a four-quasiparticle isomer band in Re174

Author

Raymond J. Carroll, Alan Mitchell, Claes Fahlander, A. Akber, T. Palazzo, R. Shearman, Andrew Stuchbery, M. S. M. Gerathy, Tibor Kibedi, V. Margerin, J. J. Carroll, P. M. Walker, Gavin Lotay, N. Palalani, Furong Xu, G. J. Lane, Matthew Reed, H. M. Albers, D. M. Cullen, S. S. Hota, Zena Patel, and A. C. Dai

Subjects
Physics, 010308 nuclear & particles physics, Excited state, 0103 physical sciences, Potential energy surface, Quasiparticle, Level structure, State (functional analysis), Atomic physics, 010306 general physics, Nucleon, Spectroscopy, 01 natural sciences
Abstract

Excited states in $^{174}\mathrm{Re}$ have been populated in fusion-evaporation reactions at the Australian National University, and $\ensuremath{\gamma}$-ray spectroscopy has been used to determine the level structure and to deduce the underlying nucleon configurations. The half-life of the bandhead of the ${K}^{\ensuremath{\pi}}={8}^{\ensuremath{-}}$ band has been measured to be 2.7(4) ns. A band built on an isomeric state of spin-parity (${14}^{\ensuremath{-}}$) and a half-life of 53(5) ns has been observed here for the first time, and has been determined to have a four-quasiparticle structure. Contrasting reduced-hindrance values for its decay are discussed in terms of deformation and configuration changes, as indicated by configuration-constrained potential energy surface calculations.

Published
2020

31. First candidates for γ vibrational bands built on the [505]11/2− neutron orbital in odd- A Dy isotopes

Author

J. Simpson, J. N. Orce, Catherine Scholey, Sanna Stolze, T. Lauritsen, A. Korichi, L. Makhathini, P. Ruotsalainen, O. Shirinda, I. Stefanescu, F. G. Kondev, J. F. Sharpey-Schafer, C. W. Beausang, D. G. Roux, N. Cooper, R. A. Bark, J. Hirvonen, Paul Greenlees, D. Miller, L. Mdletshe, B. J. P. Gall, V. Werner, E. A. McCutchan, S. N. T. Majola, E. A. Lawrie, X. Wang, Pauli Peura, J. L. Wood, S. Miller, J. Ndayishimye, C. J. Chiara, S. P. Bvumbi, Juha Sorri, Juha Uusitalo, D. Hartley, L. L. Riedinger, N. Redon, L. Bianco, Jan Sarén, S. H. Mthembu, M. A. Riley, L. Msebi, S. S. Ntshangase, Ulrika Jakobsson, B. Maqabuka, T. S. Dinoko, W. D. Kulp, J. M. Allmond, M. P. Carpenter, Peter B. Jones, G. Zimba, B. M. Nyakó, Rauno Julin, József Tímár, S. Zhu, B. V. Kheswa, Paivi Nieminen, T. D. Bucher, M. A. Sithole, P. Z. Ngcobo, Panu Rahkila, Sakari Juutinen, D. Curien, A. Minkova, D. M. Cullen, J. Piot, Steffen Ketelhut, C. H. Yu, P. L. Masiteng, and P. E. Garrett

Subjects
Physics, Coupling, Isotope, 010308 nuclear & particles physics, Nuclear structure, 01 natural sciences, 7. Clean energy, Excited state, 0103 physical sciences, Vibrational bands, Neutron, Gammasphere, Atomic physics, 010306 general physics, Spin (physics)
Abstract

Rotational structures have been measured using the Jurogam II and GAMMASPHERE arrays at low spin following the Gd155(α,2n)Dy157 and Nd148(C12,5n)Dy155 reactions at 25 and 65 MeV, respectively. We report high-K bands, which are conjectured to be the first candidates of a Kπ=2+γ vibrational band, built on the [505]11/2− neutron orbital, in both odd-ADy155,157 isotopes. The coupling of the first excited K=0+ states or the so-called β vibrational bands at 661 and 676 keV in Dy154 and Dy156 to the [505]11/2− orbital, to produce a Kπ=11/2− band, was not observed in both Dy155 and Dy157, respectively. The implication of these findings on the interpretation of the first excited 0+ states in the core nuclei Dy154 and Dy156 are also discussed.

Published
2020

32. An open source heterogeneous 3D printed mouse phantom utilising a novel bone representative thermoplastic

Author

Karen J. Kirkby, A. Subiel, Gareth J Price, A P Robinson, Sean Collins, Giuseppe Schettino, Jill Tipping, A. Aitkenhead, Emma R. Biglin, D. M. Cullen, and Amy L. Chadwick

Subjects
Radiobiology, medicine.medical_treatment, Computed tomography, Radiation, Imaging phantom, Bone and Bones, 030218 nuclear medicine & medical imaging, 03 medical and health sciences, Mice, 0302 clinical medicine, medicine, Dosimetry, Animals, Radiology, Nuclear Medicine and imaging, Radiometry, Image resolution, Manchester Cancer Research Centre, Radiological and Ultrasound Technology, medicine.diagnostic_test, Phantoms, Imaging, ResearchInstitutes_Networks_Beacons/mcrc, Attenuation, Temperature, Radiation therapy, Tissue equivalent, Mockup, 030220 oncology & carcinogenesis, Printing, Three-Dimensional, Anthropomorphic phantom, Tomography, Tomography, X-Ray Computed, Plastics, Biomedical engineering
Abstract

Introduction: The lack of rigorous quality standards in pre-clinical radiation dosimetry has renewed interest in the development of anthropomorphic phantoms. Using 3D printing customisable phantoms can be created to assess all parts of pre-clinical radiation research: planning, image guidance and treatment delivery. We present the full methodology, including material development and printing designs, for the production of a high spatial resolution, anatomically realistic heterogeneous small animal phantom. Methods: A methodology for creating and validating tissue equivalent materials is presented. The technique is demonstrated through the development of a bone-equivalent material. This material is used together with a soft-tissue mimicking ABS plastic filament to reproduce the corresponding structure geometries captured from a CT scan of a nude mouse. Air gaps are used to represent the lungs. Phantom validation was performed through comparison of the geometry and X-ray attenuation of CT images of the phantom and animal images. Results: A 6.6% difference in the attenuation of the bone-equivalent material compared to the reference standard in softer beams (0.5 mm Cu HVL) rapidly decreases as the beam is hardened. CT imaging shows accurate (sub-millimetre) reproduction of the skeleton (Distance-To-Agreement 0.5 mm ± 0.4 mm) and body surface (0.7 mm ± 0.5 mm). Histograms of the voxel intensity profile of the phantom demonstrate suitable similarity to those of both the original mouse image and that of a different animal. Conclusions: We present an approach for the efficient production of an anthropomorphic phantom suitable for the quality assurance of pre-clinical radiotherapy. Our design and full methodology are provided as open source to encourage the pre-clinical radiobiology community to adopt a common QA standard.

Published
2020

33. Testing ab initio nuclear structure in neutron-rich nuclei: Lifetime measurements of second 2+ state in C16 and O20

Author

M. Ciemała, S. Ziliani, F. C. L. Crespi, S. Leoni, B. Fornal, A. Maj, P. Bednarczyk, G. Benzoni, A. Bracco, C. Boiano, S. Bottoni, S. Brambilla, M. Bast, M. Beckers, T. Braunroth, F. Camera, N. Cieplicka-Oryńczak, E. Clément, S. Coelli, O. Dorvaux, S. Erturk, G. de France, C. Fransen, A. Goldkuhle, J. Grębosz, M. N. Harakeh, Ł. W. Iskra, B. Jacquot, A. Karpov, M. Kicińska-Habior, Y. Kim, M. Kmiecik, A. Lemasson, S. M. Lenzi, M. Lewitowicz, H. Li, I. Matea, K. Mazurek, C. Michelagnoli, M. Matejska-Minda, B. Million, C. Müller-Gatermann, V. Nanal, P. Napiorkowski, D. R. Napoli, R. Palit, M. Rejmund, Ch. Schmitt, M. Stanoiu, I. Stefan, E. Vardaci, B. Wasilewska, O. Wieland, M. Zieblinski, M. Zielińska, A. Ataç, D. Barrientos, B. Birkenbach, A. J. Boston, B. Cederwall, L. Charles, J. Collado, D. M. Cullen, P. Désesquelles, C. Domingo-Pardo, J. Dudouet, J. Eberth, V. González, J. Goupil, L. J. Harkness-Brennan, H. Hess, D. S. Judson, A. Jungclaus, W. Korten, M. Labiche, A. Lefevre, R. Menegazzo, D. Mengoni, J. Nyberg, R. M. Perez-Vidal, Zs. Podolyak, A. Pullia, F. Recchia, P. Reiter, F. Saillant, M. D. Salsac, E. Sanchis, O. Stezowski, Ch. Theisen, J. J. Valiente-Dobón, J. D. Holt, J. Menéndez, A. Schwenk, and J. Simonis

Subjects
Physics, 010308 nuclear & particles physics, 0103 physical sciences, Nuclear structure, Ab initio, Neutron, State (functional analysis), Atomic physics, 010306 general physics, 7. Clean energy, 01 natural sciences, Nuclear theory
Abstract

To test the predictive power of ab initio nuclear structure theory, the lifetime of the second 2(+) state in neutron-rich O-20, tau(2(2)(+)) = 150(-30)(+80) fs, and an estimate for the lifetime of ...

Published
2020

34. Isospin Properties of Nuclear Pair Correlations from the Level Structure of the Self-Conjugate Nucleus Ru88

Author

Eric Clément, B. Birkenbach, M. Zielińska, B. Million, M. Doncel, C. Domingo-Pardo, F. Recchia, J. Ljungvall, R. M. Perez-Vidal, Torbjörn Bäck, P. Reiter, P. Bednarczyk, J. Simpson, D. Mengoni, J. J. Valiente-Dobón, A. Lemasson, W. Korten, W. Zhang, X. Liu, B. M. Nyako, A. J. Boston, J. Goupil, H. Al-Azri, Diego Barrientos, M. D. Salsac, F. C. L. Crespi, A. Jungclaus, A. Gadea, A. Maj, N. Erduran, P. Désesquelles, A. Gottardo, Ch. Theisen, T. Hüyük, János Timár, Alberto Pullia, Vicente González, L. Charles, Zs. Podolyák, R. Menegazzo, C. M. Petrache, D. M. Cullen, S. Erturk, A. Ataç Nyberg, M. Jurado, Herbert Hess, Chong Qi, O. Aktas, Bo Cederwall, István Kuti, D. R. Napoli, Johan Nyberg, Alain Goasduff, D. Ralet, Enrique Sanchis, A. Ertoprak, M. Palacz, F. Saillant, D. Sohler, O. Stezowski, R. Wadsworth, J. Dudouet, G. de Angelis, M. Ciemala, G. Jaworski, J. Eberth, H. C. Boston, G. Benzoni, I. Burrows, and S. Leoni

Subjects
Physics, Isovector, Isoscalar, Nuclear Theory, General Physics and Astronomy, 01 natural sciences, Charged particle, Nuclear physics, 13. Climate action, Isospin, Excited state, 0103 physical sciences, Neutron detection, AGATA, Neutron, Nuclear Experiment, 010306 general physics
Abstract

The low-lying energy spectrum of the extremely neutron-deficient self-conjugate (N = Z) nuclide 88 44Ru44 has been measured using the combination of the Advanced Gamma Tracking Array (AGATA) spectrometer, the NEDA and Neutron Wall neutron detector arrays, and the DIAMANT charged particle detector array. Excited states in 88Ru were populated via the 54Fe(36Ar; 2n )88Ru fusion-evaporation reaction at the Grand Acc�el�erateur National d'Ions Lourds (GANIL) accelerator complex. The observed -ray cascade is assigned to 88Ru using clean prompt - -2-neutron coincidences in anti-coincidence with the detection of charged particles, con�rming and extending the previously assigned sequence of low-lying excited states. It is consistent with a moderately deformed rotating system exhibiting a band crossing at a rotational frequency that is significantly higher than standard theoretical predictions with isovector pairing, as well as observations in neighboring N > Z nuclides. The direct observation of such a \delayed" rotational alignment in a deformed N = Z nucleus is in agreement with theoretical predictions related to the presence of strong isoscalar neutron-proton pair correlations.

Published
2020

35. Delayed or absent π(h11/2)2 alignment in Xe111

Author

C. Scholey, A. Thornthwaite, Michael Drummond, H. C. Boston, Sanna Stolze, K. Mulholland, Panu Ruotsalainen, A. J. Boston, Baharak Hadinia, B. Saygi, M. Labiche, T. Grahn, S. Juutinen, L. Bianco, David O'Donnell, Juha Uusitalo, Paul Greenlees, D. M. Cullen, Jan Sarén, K. G. Leach, Mikael Sandzelius, Ulrika Jakobsson, X. Derkx, R. Julin, J. F. Smith, L. Capponi, Pauli Peura, Paivi Nieminen, Michael Taylor, Matti Leino, Juha Sorri, P. Rahkila, C. McPeake, D. T. Joss, E. S. Paul, and L. Grocutt

Subjects
Physics, Proton, Pi, Gamma spectroscopy, Alpha decay, Deformation (meteorology), Molecular physics
Published
2020

36. Low-lying electric dipole gamma-continuum for the unstable Fe-62,64 nuclei : Strength evolution with neutron number

Author

Eric Clément, B. Birkenbach, A. I. Morales, D. Bazzacco, H. J. Wollersheim, J. J. Valiente-Dobón, D. M. Cullen, L. J. Harkness-Brennan, M. Kmiecik, Alberto Pullia, C. Domingo-Pardo, Luis Sarmiento, C. Nociforo, N. Goel, B. Bruyneel, G. Rainovski, M.D. Salsac, S. Pietri, Begoña Quintana, J. Simpson, Pavel Golubev, T. Habermann, Johan Nyberg, R. Menegazzo, S. Leoni, M. Reese, V. Yu. Ponomarev, A. Maj, T. Arici, A. Gottardo, N. Kurz, M. Górska, S. Brambilla, I. Kojouharov, E. Merchan, M. L. Cortés, Stefano Riboldi, Enrique Sanchis, N. Lalović, Vicente González, R. Avigo, Norbert Pietralla, P. Reiter, F. Camera, M. Labiche, Zs. Podolyák, J. Gerl, D. Ralet, F. Ameil, Andreas Görgen, A. Gadea, A. Bracco, A. Jungclaus, G. Benzoni, O. Stezowski, Dirk Rudolph, D. Curien, J. Eberth, H. C. Boston, S. Bottoni, W. Korten, F. C. L. Crespi, N. Blasi, H. Schaffner, D. Mengoni, M. Lettmann, G. Duchêne, Diego Barrientos, P. H. Regan, F. Didierjean, M. Ciemala, P. Bednarczyk, G. Guastalla, B. Million, E. Gregor, Oliver Wieland, F. Recchia, D. R. Napoli, A. Atac, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Grand Accélérateur National d'Ions Lourds (GANIL), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Institut Pluridisciplinaire Hubert Curien (IPHC), Université de Strasbourg (UNISTRA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), 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), Istituto Nazionale di Fisica Nucleare, Science and Technology Facilities Council (UK), Swedish Research Council, Federal Ministry of Education and Research (Germany), European Commission, Generalitat Valenciana, Ministerio de Economía y Competitividad (España), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Nuclear and High Energy Physics, Phonon, Astrophysics::High Energy Astrophysical Phenomena, Binding energy, Nuclear Theory, Coulomb excitation, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 7. Clean energy, 01 natural sciences, 64Fe, Dipole excitation around neutron threshold, 62Fe, Subatomär fysik, 0103 physical sciences, Subatomic Physics, ddc:530, Neutron, Nuclear Physics - Experiment, Nuclear structure, 010306 general physics, Nuclear Experiment, Physics, 010308 nuclear & particles physics, 62 Fe, Fe, 64, 64 Fe, lcsh:QC1-999, Dipole, Fe-64, Neutron number, Fe-62, AGATA, Atomic physics, lcsh:Physics
Abstract

6 pags., 4 figs., The γ-ray emission from the nuclei Fe following Coulomb excitation at bombarding energy of 400-440 AMeV was measured with special focus on E1 transitions in the energy region 4-8 MeV. The unstable neutron-rich nuclei Fe were produced at the FAIR-GSI laboratories and selected with the FRS spectrometer. The γ decay was detected with AGATA. From the measured γ-ray spectra the summed E1 strength is extracted and compared to microscopic quasi-particle phonon model calculations. The trend of the E1 strength with increasing neutron number is found to be fairly well reproduced with calculations that assume a rather complex structure of the 1 states (three-phonon states) inducing a strong fragmentation of the E1 nuclear response below the neutron binding energy., This work was partially supported by INFN (Italy) and STFC (UK), the Swedish Research Council (Vetenskapsrådet, VR 2010-147, 2011-5253, and 2016-3969), BMBF NuSTAR-AGATA 05P18RDFN9 and BMBF NuSTAR 05P18RDFN1. The project was co-funded by the European Commission under the 7th Framework Program for RTD (2007-2013) under the Capacities Program (Contract Number 262010, ENSAR). This work was par-tially supported by the Ministry of Science, and Generalitat Valenciana, Spain, under the Grants SEV-2014-0398, FPA2017-84756-C4, PROMETEO/2019/005 and by the EU FEDER funds.

Published
2020

37. Pairing-quadrupole interplay in the neutron-deficient tin nuclei: First lifetime measurements of low-lying states in 106,108Sn

Author

R. M. Perez-Vidal, T. Marchi, P. Reiter, Georgi P. Georgiev, Andrés P. Zuker, C. Fransen, D. Mengoni, J. Dudouet, Bo Cederwall, C. Theisen, C. Domingo-Pardo, Thomas Braunroth, A. Goasduff, O. Stezowski, W. Korten, F. C. L. Crespi, A. J. Boston, Johan Nyberg, C. Michelagnoli, B. Birkenbach, Vicente González, C. Müller-Gatermann, Tea Mijatović, D. Bazzacco, Hui Li, Enrique Sanchis, D. S. Judson, N. Cieplicka-Oryńczak, B. Million, Diego Barrientos, S. Leoni, M. Labiche, L. J. Harkness-Brennan, A. Jungclaus, F. Recchia, D. Testov, F.J. Egea-Canet, Herbert Hess, J. Eberth, H. C. Boston, A. Lefevre, J. Collado, István Kuti, A. Lemasson, Dóra Sohler, Alberto Pullia, M. D. Salsac, M. Siciliano, A. Gadea, D. R. Napoli, G. Jaworski, A. Lopez-Martens, S. Szilner, G. Benzoni, Maria Doncel, Eric Clément, M. Palacz, P. R. John, M. Zielińska, P. Désesquelles, B. Sayği, Ulrika Jakobsson, J. J. Valiente-Dobón, A. Maj, R. Menegazzo, S. Erturk, F. Nowacki, D. M. Cullen, A. Goldkuhle, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut Pluridisciplinaire Hubert Curien (IPHC), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Grand Accélérateur National d'Ions Lourds (GANIL), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut Laue-Langevin (ILL), ILL, Institut de Physique Nucléaire de Lyon (IPNL), 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)-Centre National de la Recherche Scientifique (CNRS), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Ege Üniversitesi, Ministerio de Ciencia e Innovación (España), Generalitat Valenciana, Université de Strasbourg (UNISTRA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)

Subjects
Nuclear and High Energy Physics, Light Sn, chemistry.chemical_element, FOS: Physical sciences, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], nucl-ex, 01 natural sciences, Subatomär fysik, Lifetime, Multi-nucleon transfer, Nuclear structure, Tracking array, 0103 physical sciences, Subatomic Physics, Neutron, Nuclear Physics - Experiment, Nuclear Experiment (nucl-ex), 010306 general physics, Nuclear Experiment, Physics, Spectrometer, Isotope, 010308 nuclear & particles physics, lcsh:QC1-999, chemistry, Pairing, Excited state, Quadrupole, AGATA, Atomic physics, Tin, lcsh:Physics
Abstract

The lifetimes of the low-lying excited states 2(+) and 4(+) have been directly measured in the neutron-deficient Sn-106,Sn-108 isotopes. the nuclei were populated via a deep-inelastic reaction and the lifetime measurement was performed employing a differential plunger device. the emitted gamma rays were detected by the AGATA array, while the reaction products were uniquely identified by the VAMOS++ magnetic spectrometer. Large-Scale Shell-Model calculations with realistic forces indicate that, independently of the pairing content of the interaction, the quadrupole force is dominant in the B(E2; 2(1)(+) -> 0(g.s)(+)) values and it describes well the experimental pattern for Sn104-114 ; the B(E2;(+)(4) -> 2(1)(+)) values, measured here for the first time, depend critically on a delicate pairing-quadrupole balance, disclosed by the very precise results in Sn-108. (C) 2020 the Authors. Published by Elsevier B.V., European Union's Seventh Framework Programme for Research and Technological DevelopmentEuropean Union (EU) [262010]; Fondazione Cassa di Risparmio Padova e Rovigo under the project CONPHYT, starting grant in 2017; Swedish Research CouncilSwedish Research Council [822-2005-3332, 821-2010-6024, 821-2013-2304, 621-20145558, 2017-0065]; Knut and Alice Wallenberg FoundationKnut & Alice Wallenberg Foundation [2005.0184]; Scientific and Technological Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [114F473]; Ministerio de Ciencia e InnovacionInstituto de Salud Carlos IIISpanish Government [SEV-2014-0398, FPA2017-84756-C4, EEBBI-15-09671]; Generalitat ValencianaGeneralitat Valenciana [PROMETEO/2019/005]; EU-FEDER fundsEuropean Union (EU); Croatian Science Foundation [7194]; Hungarian National Research and Innovation Office (NKFIH) [K128947, PD124717, GINOP-2.3.3-15-2016-00034]; Polish National Science Centre under the COPIN-IN2P3 project [2014-14-M-ST2-00738, 2016-22M-ST2-00269, 2017-25-B-ST2-01569]; Polish National Science Centre under the COPIGAL project [2014-14-M-ST2-00738, 2016-22M-ST2-00269, 2017-25-B-ST2-01569]; Polish National Science Centre under the POLITA project [2014-14-M-ST2-00738, 2016-22M-ST2-00269, 2017-25-B-ST2-01569], The authors would like to thank the AGATA and VAMOS collaborations. Special thanks go to the GANIL technical staff for their help in setting up the apparatuses and the good quality beam and to A. Poves for his fruitful comments. This work was partially supported by the European Union's Seventh Framework Programme for Research and Technological Development (grant no. 262010). A.G. acknowledges the support of the Fondazione Cassa di Risparmio Padova e Rovigo under the project CONPHYT, starting grant in 2017. the work was also supported (B.C, H.L., J.N. and U.J.) by Swedish Research Council under the grant agreements nos. 822-2005-3332, 821-2010-6024, 821-2013-2304, 621-20145558 and 2017-0065, and by the Knut and Alice Wallenberg Foundation grant no. 2005.0184, (B.S.) by the Scientific and Technological Council of Turkey (TUBITAK) under the project no. 114F473, (A.G., A.J. and R.P.) by the Ministerio de Ciencia e Innovacion under the contracts nos. SEV-2014-0398, FPA2017-84756-C4 and EEBBI-15-09671, by the Generalitat Valenciana under the grant agreement no. PROMETEO/2019/005 and by the EU-FEDER funds, (T.M and S.S.) by the Croatian Science Foundation under the project no. 7194, (I.K and D.S.) by the Hungarian National Research and Innovation Office (NKFIH) under the project nos. K128947, PD124717 and GINOP-2.3.3-15-2016-00034, (M.P.) by the Polish National Science Centre with the grants nos. 2014-14-M-ST2-00738, 2016-22M-ST2-00269 and 2017-25-B-ST2-01569 under the COPIN-IN2P3, COPIGAL and POLITA projects.

Published
2020

38. Benchmarking the PreSPEC@GSI experiment for Coulex-multipolarimetry on the $\pi (p_{3/2})\rightarrow \pi (p_{1/2})$ spin-flip transition in $^{85}$Br

Author

Diego Barrientos, M. Labiche, L. Grassi, J. Eberth, Claes Fahlander, V. Modamio, I. Kojouharov, B. Birkenbach, O. Möller, H. Egger, F. C. L. Crespi, P. Désesquelles, C. Domingo-Pardo, S. Afara, W. Korten, A. Bracco, B. S. Nara Singh, D. M. Cullen, Enrique Sanchis, M. Lettmann, Pavel Golubev, Oliver Wieland, J. Gerl, B. Bruyneel, G. Rainovski, Dirk Rudolph, A. Maj, Norbert Pietralla, A. Blazhev, P. R. John, A. Gottardo, D. Curien, P. Bednarczyk, B. Million, Luis Sarmiento, T. Arici, Pushpendra Singh, S. Aydin, E. Merchan, P. Reiter, F. Ameil, S. Pietri, J. Simpson, Eric Clément, J. Jolie, C. Stahl, K. A. Gladnishki, K. Moschner, Herbert Hess, A. J. Boston, D. Ralet, M. L. Cortés, N. Lalović, C. Louchart-Henning, M. A. Bentley, D. S. Judson, H. Schaffner, J. J. Valiente-Dobón, P. Boutachkov, Roberto Menegazzo, D. Mengoni, M. Reese, V. Werner, G. Duchêne, L. J. Harkness-Brennan, G. Benzoni, D. R. Napoli, Vicente González, F. Didierjean, Zs. Podolyák, T. Möller, C. Lizarazo, P. Napiralla, M. Górska, T. Habermann, D. G. Jenkins, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Grand Accélérateur National d'Ions Lourds (GANIL), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Institut Pluridisciplinaire Hubert Curien (IPHC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Institut de Physique Nucléaire d'Orsay (IPNO), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Hadron, Coulomb excitation, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Nuclear physics, Transition strength, 0103 physical sciences, Nuclear fusion, AGATA, Spin-flip, 010306 general physics, Beam (structure)
Abstract

International audience; A first performance test of the Coulomb excitation multipolarimetry (Coulex-multipolarimetry) method is presented. It is based on a $^{85}\hbox {Br}\,\pi p_{3/2}\rightarrow \pi p_{1/2}$ spin-flip experiment performed as part of the PreSPEC-AGATA campaign at the GSI Helmholtzzentrum für Schwerionenforschung (GSI). Via determination of background levels around the expected $^{85}\hbox {Br}$ excitations as well as measured $^{197}\hbox {Au}$ excitations, an upper limit for the M1 transition strength of the $1/2_1^-\rightarrow 3/2_\text {g.s.}^-$ transition in $^{85}\hbox {Br}$ and a lower beam time limit for upcoming experimental campaigns utilizing Coulex-multipolarimetry have been inferred. The impact of the use of AGATA in its anticipated $1\pi $ configuration on these estimates is deduced via Geant4 simulations.

Published
2020

39. Evidence for octupole collectivity in $^{172}{\mathrm {Pt}}$

Author

E. Ganioglu, Rauno Julin, I. Özgür, R. D. Page, Eiji Ideguchi, O. Aktas, Sanna Stolze, E. S. Paul, J. Hilton, Torbjörn Bäck, H. W. Li, J. J. Valiente-Dobón, S. Matta, Mikael Sandzelius, Steffen Ketelhut, B. S. Nara Singh, Panu Rahkila, Tuomas Grahn, U. Jakobsson, Panu Ruotsalainen, C. M. Petrache, Megumi Niikura, D. M. Cullen, Jari Partanen, K. Andgren, Janne Pakarinen, Bo Cederwall, A. Ertoprak, B. Hadinia, D. Hodge, M. Kumar Raju, T. Calverley, Juha Sorri, Juha Uusitalo, V. Modamio, H. Badran, Paul Greenlees, Chong Qi, M. Nyman, Pauli Peura, Daniel Cox, A. Johnson, Jan Sarén, Y. D. Fang, Peter M. Jones, Michael Taylor, Matti Leino, Ramon Wyss, Thomas Braunroth, Catherine Scholey, H. Liu, Sakari Juutinen, Roberto Liotta, M. B. Gomez Hornillos, M. Doncel, M. M. Giles, P. Subramaniam, Philippos Papadakis, Anton Khaplanov, Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), and Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Hadron, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Nuclear physics, medicine.anatomical_structure, Excited state, 0103 physical sciences, medicine, Nuclear fusion, 010306 general physics, Nucleus, Excitation
Abstract

Excited states in the extremely neutron-deficient nucleus $$^{172}{\mathrm {Pt}}$$172Pt were populated via $$^{96}\mathrm {Ru}(^{78}\mathrm {Kr},2p)$$96Ru(78Kr,2p) and $$^{92}\mathrm {Mo}(^{83}\mathrm {Kr},3n)$$92Mo(83Kr,3n) reactions. The level scheme has been extended up to an excitation energy of $$\approx 5~\hbox {MeV}$$≈5MeV and tentative spin-parity assignments up to $$I^\pi = 18^+$$Iπ=18+. Linear polarization and angular distribution measurements were used to determine the electromagnetic E1 character of the dipole transitions connecting the positive-parity ground-state band with an excited side-band, firmly establishing it as a negative-parity band. The lowest member of this negative-parity structure was firmly assigned spin-parity $$3^-$$3-. In addition, we observed an E3 transition from this $$3^-$$3- state to the ground state, providing direct evidence for octupole collectivity in $$^{172}{\mathrm {Pt}}$$172Pt. Large-scale shell model (LSSM) and total Routhian surface (TRS) calculations have been performed, supporting the interpretation of the $$3^-$$3- state as a collective octupole-vibrational state.

Published
2020

40. FATIMA — FAst TIMing Array for DESPEC at FAIR

Author

V. F. E. Pucknell, C. R. Nita, I. Burrows, J. Vesic, C. Townsley, L. M. Fraile, J. Gerl, R. Canavan, J.-M. Régis, L. M. Gerhard, J. Simpson, E.R. Gamba, I.H. Lazarus, D. M. Cullen, P. H. Regan, Alison Bruce, M. Rudigier, H. Schaffner, J. Jolie, Alec Grant, Pushpendra Singh, S. Lalkovski, Oliver J. Roberts, W. Korten, V. Karayonchev, J. F. Smith, N. Kurz, M. Górska, Zs. Podolyák, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay

Subjects
Nuclear and High Energy Physics, Fast timing, Scintillator, NuSTAR, 01 natural sciences, Coincidence, DESPEC, Optics, Data acquisition, 0103 physical sciences, LaBr 3 (Ce) scintillator detectors, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], 010306 general physics, Instrumentation, FAIR, Physics, 010308 nuclear & particles physics, business.industry, Detector, Centroid, Full width at half maximum, Cascade, LaBr[formula omitted](Ce) scintillator detectors, business, Energy (signal processing)
Abstract

Nuclear instruments & methods in physics research / A Accelerators, spectrometers, detectors and associated equipment Section A 969, 163967 (2020). doi:10.1016/j.nima.2020.163967, Published by North-Holland Publ. Co., Amsterdam

Published
2020

42. Lifetime measurements in Ti52,54 to study shell evolution toward N=32

Author

A. Lemasson, W. Korten, Thomas Braunroth, Herbert Hess, C. Müller-Gatermann, C. Domingo-Pardo, J. Simpson, I. Burrows, S. Leoni, P. Reiter, C. Fransen, A. Vogt, Bertrand Jacquot, C. Houarner, D. M. Cullen, C. Henrich, A. Lefevre, A. Atac, M. Zielińska, M. Ciemala, N. Ménard, F. Legruel, A. J. Boston, J. Eberth, A. Goldkuhle, M. Labiche, H. C. Boston, Alberto Pullia, G. Voltolini, K. O. Zell, A. Korichi, J. Ljungvall, R. M. Pérez-Vidal, L. Ménager, J.-L. Foucher, C. Barthe-Dejean, C. Michelagnoli, Diego Barrientos, A. Dewald, J. Ropert, B. Birkenbach, Y. H. Kim, O. Stezowski, P. Bourgault, A. Blazhev, G. Frémont, J. Goupil, D. Ralet, Bo Cederwall, G. Benzoni, Ch. Theisen, N. Warr, A. Gadea, H. J. Li, A. Maj, Johan Nyberg, M. D. Salsac, S. M. Lenzi, M. Jean, J. J. Valiente Dobon, C. Maugeais, L. Legeard, P. Gangnant, A. Navin, M. Ozille, B. Million, M. Tripon, B. S. Nara Singh, Enrique Sanchis, D. R. Napoli, Emyr Clement, J. Dudouet, F. Saillant, Vicente González, F. Recchia, Ch. Schmitt, H. Munoz, Zs. Podolyák, B. Raine, M. Beckers, Roberto Menegazzo, D. Mengoni, J. Cacitti, J. Litzinger, J. Jolie, D. S. Judson, C. Spitaels, and M. Toulemonde

Subjects
Plunger, Physics, 010308 nuclear & particles physics, Excited state, Nuclear Theory, 0103 physical sciences, Shell (structure), Atomic physics, Nuclear Experiment, 010306 general physics, 7. Clean energy, 01 natural sciences
Abstract

Lifetimes of the excited states in the neutron-rich Ti-52,Ti-54 nuclei, produced in a multinucleon-transfer reaction, were measured by employing the Cologne plunger device and the recoil-distance D ...

Published
2019

43. α -decay spectroscopy of the N=130 isotones Ra218 and Th220 : Mitigation of α -particle energy summing with implanted nuclei

Author

Michael Taylor, S. Juutinen, D. Mengoni, M. Smolen, Matti Leino, Philippos Papadakis, Sanna Stolze, Tuomas Grahn, R.-D. Herzberg, J. M. Keatings, Juha Uusitalo, A. Herzáň, D. M. Cullen, Panu Ruotsalainen, Robert Chapman, Jan Sarén, D. Hodge, Jari Partanen, Janne Pakarinen, Joonas Konki, C. Scholey, Juha Sorri, Liam Gaffney, L. Grocutt, K. Mulholland, A. K. Mistry, B. S. Nara Singh, Daniel Cox, Pauli Peura, P. P. McKee, Paul Greenlees, Panu Rahkila, P. Spagnoletti, J. F. Smith, E. T. Gregor, P. A. Butler, G. G. O'Neill, K. M. Spohr, Mikael Sandzelius, Marcus Scheck, E. Parr, Ulrika Jakobsson, M. Siciliano, C. McPeake, Kalle Auranen, and Rauno Julin

Subjects
Physics, 010308 nuclear & particles physics, Branching fraction, 0103 physical sciences, Silicon detector, Atomic physics, 010306 general physics, Spectroscopy, 01 natural sciences, α particles, Energy (signal processing)
Abstract

© 2019 American Physical Society. An analysis technique has been developed in order to mitigate energy summing due to sequential short-lived α decays from nuclei implanted into a silicon detector. Using this technique, α-decay spectroscopy of the N=130 isotones Ra218 (Z=88) and Th220 (Z=90) has been performed. The energies of the α particles emitted in the Ra218→Rn214 and Th220→Ra216 ground-state-to-ground-state decays have been measured to be 8381(4) keV and 8818(13) keV, respectively. The half-lives of the ground states of Ra218 and Th220 have been measured to be 25.99(10) μs and 10.4(4) μs, respectively. The half-lives of the ground states of the α-decay daughters, Rn214 and Ra216, have been measured to be 259(3) ns and 161(11) ns, respectively. Fine structure in the α decay of Ra218 has been observed for the first time, populating the 695-keV 21+ state in Rn214. The fine-structure α decay has an α-particle energy of 7715(40) keV and branching ratio bα=0.123(11)%.

Published
2019

44. β and γ bands in N=88 , 90, and 92 isotones investigated with a five-dimensional collective Hamiltonian based on covariant density functional theory: Vibrations, shape coexistence, and superdeformation

Author

B. V. Kheswa, Peter B. Jones, A. Minkova, Z. P. Li, D. Negi, D. M. Cullen, R. Lindsay, O. Shirinda, B. M. Nyakó, R. A. Bark, R. Newman, T. S. Dinoko, D. G. Aschman, Jan Sarén, P. I. Mashita, L. L. Riedinger, R. Ntshodu, J. E. Easton, J. Hirvonen, S. Jongile, P. Papka, L. Msebi, Sanna Stolze, J. F. Sharpey-Schafer, N. A. Khumalo, Ulrika Jakobsson, M. Wiedeking, E. A. Lawrie, S. P. Bvumbi, Paul Greenlees, A. Korichi, Juha Sorri, P. Ruotsalainen, M. Stankiewicz, A. Netshiya, S. S. Ntshangase, Sakari Juutinen, Catherine Scholey, József Tímár, J. Ndayishimye, M. A. Riley, D. G. Roux, S. N. T. Majola, Pauli Peura, Steffen Ketelhut, K. L. Malatji, D. Hartley, T. E. Madiba, S. M. Mullins, P. A. Vymers, S. Q. Zhang, M. A. Sithole, Juha Uusitalo, P. L. Masiteng, T. D. Bucher, B. Y. Song, L. Makhathini, Panu Rahkila, N. Erasmus, G. Zimba, Z. Shi, S. M. Maliage, B. Maqabuka, L. Mdletshe, J. J. Lawrie, and Rauno Julin

Subjects
Physics, 010308 nuclear & particles physics, Nuclear structure, 01 natural sciences, Hamiltonian system, Superdeformation, Vibration, symbols.namesake, Quantum mechanics, 0103 physical sciences, symbols, Density functional theory, Covariant transformation, 010306 general physics, Hamiltonian (quantum mechanics)
Abstract

CITATION: Majola, S. N. T. et al. 2019. β and γ bands in N=88, 90, and 92 isotones investigated with a five-dimensional collective Hamiltonian based on covariant density functional theory: Vibrations, shape coexistence, and superdeformation. Physical Review C, 100(4). doi:10.1103/PhysRevC.100.044324.

Published
2019

45. Fast-timing measurements in the ground-state band of Pd114

Author

T. Lauritsen, T. Kröll, L. A. Gurgi, F. G. Kondev, G. J. Lane, I. Burrows, D. M. Cullen, O. Yordanov, S. Lalkovski, Alison Bruce, John P. Greene, T. Daniel, V. F. E. Pucknell, D. Seweryniak, D. J. Hartley, Gavin Lotay, C. M. Shand, M. Smolen, T. Berry, S. Bottoni, C. R. Niţă, E. A. Stefanova, J. Sethi, E.R. Gamba, R. Ilieva, M. Carmona Gallardo, S. Zhu, J. Rohrer, J. T. Anderson, A. D. Ayangeakaa, S. Ilieva, J. Simpson, Matthew Reed, M. P. Carpenter, P. Copp, M. Rudigier, V. Vedia, I.H. Lazarus, P. H. Regan, Raymond J. Carroll, Zs. Podolyák, and G. Fernández Martínez

Subjects
Physics, Work (thermodynamics), Isotope, Yrast, chemistry.chemical_element, medicine.anatomical_structure, chemistry, medicine, Gammasphere, Interacting boson model, Atomic physics, Ground state, Nucleus, Palladium
Abstract

Using a hybrid Gammasphere array coupled to 25 LaBr3(Ce) detectors, the lifetimes of the first three levels of the yrast band in ¹¹⁴Pd populated via ²⁵²Cf decay, have been measured. The measured lifetimes are τ₂+=103(10)ps, τ₄+=22(13)ps, and τ₆+≤10ps for the 2⁺₁, 4⁺₁, and 6⁺₁ levels, respectively. Palladium-114 was predicted to be the most deformed isotope of its isotopic chain, and spectroscopic studies have suggested it might also be a candidate nucleus for low-spin stable triaxiality. From the lifetimes measured in this work, reduced transition probabilities B(E2;J→J−2) are calculated and compared with interacting boson model, projected shell model, and collective model calculations from the literature. The experimental ratio RB(E₂)=B(E2;4⁺₁→2⁺₁)/B(E2;2⁺₁→0⁺₁)=0.80(42) is measured for the first time in ¹¹⁴Pd and compared with the known values RB(E₂) in the palladium isotopic chain: the systematics suggest that, for N=68, a transition from γ-unstable to a more rigid γ-deformed nuclear shape occurs.

Published
2019

46. Spectroscopy of low-spin states in Dy157 : Search for evidence of enhanced octupole correlations

Author

L. Bianco, Robert Bark, B. M. Nyakó, T. D. Bucher, P. L. Masiteng, J. Ndayishimye, Steffen Ketelhut, E. A. Lawrie, G. Zimba, L. Mdletshe, O. Shirinda, Peter B. Jones, C. Scholey, S. S. Ntshangase, D. M. Cullen, R. T. Newman, Pauli Peura, D. J. Hartley, S. N. T. Majola, J.F. Sharpey-Schafer, A. Minkova, S. P. Bvumbi, B. V. Kheswa, B. Maqabuka, Ulrika Jakobsson, Juha Sorri, Juha Uusitalo, P. Ruotsalainen, S. Juutinen, J. Hirvonen, M. A. Riley, Sanna Stolze, József Tímár, P. Rahkila, D. G. Roux, P. E. Garrett, A. Sithole, Paivi Nieminen, R. Julin, L. L. Riedinger, Jan Sarén, A. Korichi, and Paul Greenlees

Subjects
Physics, Nuclear physics, Spin states, 010308 nuclear & particles physics, 0103 physical sciences, Nuclear structure, 010306 general physics, Spectroscopy, 01 natural sciences, Nuclear theory, 3. Good health
Abstract

CITATION: Majola, S. N. T., et al. 2019. Spectroscopy of low-spin states in 157Dy : Search for evidence of enhanced octupole correlations. Physical Review C, 100(6):034322, doi:10.1103/PhysRevC.100.034322.

Published
2019

47. Evidence of octupole-phonons at high spin in 207Pb

Author

B. Quintana Arnés, G. Bocchi, R. Perez, Raymond J. Carroll, W. Korten, Alberto Pullia, M. Labiche, Zs. Podolyák, A. Navin, Enrique Sanchis, F. Saillant, Norbert Pietralla, F. C. L. Crespi, C. M. Shand, E. Dupont, B. Fornal, D. Kocheva, Diego Barrientos, O. Stezowski, P. Reiter, L. Atanasova, M. Ciemala, Herbert Hess, Roberto Menegazzo, D. Mengoni, B. Birkenbach, J. Collado, H.J. Eberth, Bo Cederwall, D. Ralet, B. Million, A. Maj, P. Van Isacker, D. Wilmsen, J. J. Valiente Dobon, J. Dudouet, F. Recchia, P. Bednarczyk, M. Rejmund, Georgi P. Georgiev, Andrew Stuchbery, A. Goasduff, A. Lemasson, Deyan Yordanov, P. R. John, Salsac, R. L. Lozeva, A. Jungclaus, C. Michelagnoli, A. Blazhev, J. Goupil, S. Franchoo, A. Gadea, L. J. Harkness, Johan Nyberg, S. M. Lenzi, D. L. Balabanski, D. M. Cullen, I. Burrows, T. Konstantinopoulos, Emyr Clement, H. C. Boston, O. Wieland, C. Theisen, A. J. Boston, A. Kusoglu, C. Fransen, A. Korichi, S. Leoni, C. Müller-Gatermann, J. Ljungvall, Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Grand Accélérateur National d'Ions Lourds (GANIL), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), 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), Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Institut Pluridisciplinaire Hubert Curien (IPHC), Université de Strasbourg (UNISTRA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Ministerio de Economía y Competitividad (España), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-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)-Centre National de la Recherche Scientifique (CNRS), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Nuclear and High Energy Physics, Plunger device, Phonon, Nuclear Theory, Octupole phonon, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], gamma-Ray tracking, γ -Ray tracking, 01 natural sciences, 7. Clean energy, Recoil, VAMOS++ spectrometer, AGATA spectrometer, Nuclear deformation, γ-Ray tracking, 0103 physical sciences, Physics::Atomic Physics, Nuclear Experiment, 010306 general physics, Spin (physics), Physics, VAMOS plus plus spectrometer, 010308 nuclear & particles physics, lcsh:QC1-999, Atomic physics, lcsh:Physics
Abstract

A lifetime measurement of the 19/2 state in Pb has been performed using the Recoil Distance Doppler-Shift (RDDS) method. The nuclei of interest were produced in multi-nucleon transfer reactions induced by a Pb beam impinging on a Mo enriched target. The beam-like nuclei were detected and identified in terms of their atomic mass number in the VAMOS++ spectrometer while the prompt γ rays were detected by the AGATA tracking array. The measured large reduced transition probability B(E3,19/2→13/2)=40(8) W.u. is the first indication of the octupole phonon at high spin in Pb. An analysis in terms of a particle-octupole-vibration coupling model indicates that the measured B(E3) value in Pb is compatible with the contributions from single-phonon and single particle E3 as well as E3 strength arising from the double-octupole-phonon 6 state, all adding coherently. A crucial aspect of the coupling model, namely the strong mixing between single-hole and the phonon-hole states, is confirmed in a realistic shell-model calculation.

Published
2019

48. Effects of one valence proton on seniority and angular momentum of neutrons in neutron-rich Sb51122–131 isotopes

Author

L. J. Harkness-Brennan, H. L. Crawford, Alberto Pullia, M. Rejmund, A. Jungclaus, B. Birkenbach, G. Benzoni, A. Lefevre, J. J. Valiente-Dobón, J. Goupil, Bo Cederwall, M. D. Salsac, P. Bednarczyk, Ch. Theisen, H. J. Li, A. J. Boston, R. Banik, Diego Barrientos, Vicente González, J. Eberth, O. Stezowski, Sumita Bhattacharyya, V. Morel, H. C. Boston, D. Ralet, D. Mengoni, A. Lemasson, D. M. Cullen, I. Stefan, Bertrand Jacquot, R. Menegazzo, D. R. Napoli, Herbert Hess, J. Collado, P. Fallon, J. Dudouet, C. Michelagnoli, R. Palit, G. Frémont, Y. H. Kim, S. Biswas, P. Désesquelles, R. M. Pérez-Vidal, M. Zielińska, Soumik Bhattacharya, A. Navin, Enrique Sanchis, F. Saillant, W. Korten, B. Million, J. Ropert, Begoña Quintana, J. Ljungvall, L. Ménager, Eric Clément, F. Recchia, A. Maj, M. Labiche, P. Reiter, and C. Domingo-Pardo

Subjects
Physics, Angular momentum, Valence (chemistry), Isotope, 010308 nuclear & particles physics, Fission, Nuclear Theory, Nuclear structure, 7. Clean energy, 01 natural sciences, Neutron number, 0103 physical sciences, AGATA, Neutron, Atomic physics, Nuclear Experiment, 010306 general physics
Abstract

Background: Levels fulfilling the seniority scheme and relevant isomers are commonly observed features in semimagic nuclei; for example, in Sn isotopes (Z=50). Seniority isomers in Sn, with dominantly pure neutron configurations, directly probe the underlying neutron-neutron (νν) interaction. Furthermore, an addition of a valence proton particle or hole, through neutron-proton (νπ) interaction, affects the neutron seniority as well as the angular momentum. Purpose: Benchmark the reproducibility of the experimental observables, like the excitation energies (EX) and the reduced electric-quadrupole transition probabilities [B(E2)], with the results obtained from shell-model interactions for neutron-rich Sn and Sb isotopes with N

Published
2019

49. Shape coexistence in Hg-178

Author

Joonas Konki, K. O. Zell, G. Fruet, Andrej Herzan, D. M. Cullen, A. Goldkuhle, Juha Sorri, Sanna Stolze, Janne Pakarinen, Mikael Sandzelius, A. Dewald, Jan Sarén, M. G. Procter, Michael Taylor, D. G. Jenkins, Sakari Juutinen, H. Badran, Matti Leino, Pauli Peura, Rauno Julin, C. Fransen, Paul Greenlees, Tuomas Grahn, K. Nomura, Catherine Scholey, M. Beckers, J. Litzinger, Ulrika Jakobsson, Panu Rahkila, Juha Uusitalo, Thomas Braunroth, J. Jolie, A. Blazhev, P. Ruotsalainen, C. Müller-Gatermann, Kalle Auranen, Department of Chemistry, and Helsinki Institute of Physics

Subjects
Physics, GE, Manchester Cancer Research Centre, 010308 nuclear & particles physics, Yrast, ResearchInstitutes_Networks_Beacons/mcrc, Nuclear structure, Prolate spheroid, Nuclear Structure, 01 natural sciences, 114 Physical sciences, LIFETIMES, PLUNGER, Recoil, STATES, Excited state, Neutron number, 0103 physical sciences, MERCURY, Atomic physics, 010306 general physics, Nuclear Experiment, Beam energy
Abstract

Lifetime measurements of excited states in Hg-178 have been performed using the Rh-103(Kr-78, p2n) reaction at a beam energy of 354 MeV. The recoil-decay tagging (RDT) technique was applied to select the Hg-178 nuclei and associate the prompt gamma rays with the correlated characteristic ground-state alpha decay. Lifetimes of the four lowest yrast states of Hg-178 have been determined using the recoil distance Doppler-shift (RDDS) method. The experimental data are compared to theoretical predictions with focus on shape coexistence. The results confirm the shift of the deformed prolate structures to higher lying states but also indicate their increasing deformation with decreasing neutron number.

Published
2019

50. Probing isospin symmetry in the (Fe50, Mn50, Cr50) isobaric triplet via electromagnetic transition rates

Author

C. Müller-Gatermann, J. Jolie, M. M. Giles, A. Dewald, F. Mammes, B. S. Nara Singh, S. M. Lenzi, M. Beckers, C. Fransen, Thomas Braunroth, D. Wölk, K. O. Zell, L. Barber, M. J. Mallaburn, D. M. Cullen, A. Goldkuhle, A. Blazhev, and Alfredo Poves

Subjects
Physics, Firm conclusion, Recoil, Isospin, Nuclear Theory, Nuclear structure, Isobaric process, Atomic physics, Nuclear Experiment, Transition rate matrix, Symmetry (physics)
Abstract

Lifetimes of the $T=1$ isobaric analog ${I}^{\ensuremath{\pi}}={2}^{+}$ states in $^{50}\mathrm{Mn}$ and $^{50}\mathrm{Cr}$ were measured simultaneously by employing the recoil distance Doppler-shift (RDDS) technique. The states were populated in a fusion-evaporation reaction with a $^{12}\mathrm{C}$ beam on a $^{40}\mathrm{Ca}$ target. An analysis of the data and the calculations from the present work, together with the available $B(E2:{2}^{+}\ensuremath{\rightarrow}{0}^{+})$ data of the isobaric analog states in $^{50}\mathrm{Fe}$ and $^{50}\mathrm{Cr}$, were used to study isospin symmetry in the three $A=50$ isobaric nuclei. Shell-model calculations reproduce the magnitudes as well as the increasing trend of the $B(E2)$ data with increasing $Z$. To draw a firm conclusion on the level of isospin mixing in the triplet, a new precision measurement of the ${2}^{+}\ensuremath{\rightarrow}{0}^{+}$ transition rate in $^{50}\mathrm{Fe}$ will be required.

Published
2019

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