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98 results on '"M, Rudigier"'

51. A revised B(E2;2+ 1 $ \rightarrow$ → 0+ 1) value in the semi-magic nucleus 210Po

Author

A. Dewald, M. Spieker, D. Kocheva, P. Scholz, C. Müller-Gatermann, R. Altenkirch, V. Karayonchev, A. Blazhev, M. Djongolov, M. Rudigier, P. Thöle, K. A. Gladnishki, Norbert Pietralla, V. Yu. Ponomarev, F. Diel, S. Ansari, D. Wölk, J. M. Keatings, N. Warr, Th. Braunroth, C. Stahl, P. Van Isacker, V. Werner, G. Rainovski, A. Astier, M. Stoyanova, A. Hennig, J. Litzinger, J. Jolie, M. L. Cortés, C. Fransen, W. Witt, K. O. Zell, E. Kluge, R. Stegmann, P. Spagnoletti, P. Petkov, and Marcus Scheck

Subjects
Physics, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Phonon, Yrast, Hadron, Value (computer science), State (functional analysis), 01 natural sciences, medicine.anatomical_structure, 0103 physical sciences, medicine, Nuclear fusion, MAGIC (telescope), Atomic physics, 010306 general physics, Nucleus
Abstract

The lifetimes of the $ 2^+_1$ , the $ 2^+_2$ and the $ 3^-_1$ states of$^{210}$Po have been measured in the$^{208}$Pb($^{12}$C,$^{10}$Be)$^{210}$Po transfer reaction by the Doppler-shift attenuation method. The result for the lifetime of the $ 2^+_1$ state is about three times shorter than the adopted value. However, the new value still does not allow for a consistent description of the properties of the yrast $ 2^+_1$ , $ 4^+_1$ , $ 6^+_1$ , and $ 8^+_1$ states of$^{210}$Po in the framework of nuclear shell models. Quasi-particle Phonon Model (QPM) calculations also cannot overcome this problem thus indicating the existence of a peculiarity which is neglected in both theoretical approaches.

Published
2017
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52. Triaxiality of neutron-rich Ge84,86,88 from low-energy nuclear spectra

Author

L. Olivier, Megumi Niikura, Alison Bruce, Tomohiro Uesaka, I. Stefan, M. Rudigier, Z. Patel, A. Giganon, A. Obertelli, C. R. Nita, Tomás R. Rodríguez, C. M. Shand, Satoru Momiyama, N. Paul, Noritsugu Nakatsuka, S. Nagamine, F. Château, Ryo Taniuchi, Bing Ding, J.-Y. Roussé, Zs. Podolyák, C. R. Nobs, K. Moschner, Zhengyu Xu, T. Arici, Zi Hong Liu, V. Werner, A. Jungclaus, Hiroyoshi Sakurai, Kathrin Wimmer, M. Górska, David Steppenbeck, C. Lizarazo, F. Flavigny, H. Baba, T. Saito, G. Authelet, Kamila Sieja, Toshiaki Ando, M. Dewald, Si-Ge Chen, P. A. Söderström, R. J. Caroll, D. Calvet, Tohru Motobayashi, P. Doornenbal, J. M. Gheller, L. X. Chung, A. Gillibert, Jian Liu, A. Blazhev, Victor Vaquero, Andrea Corsi, M. Lettmann, F. Browne, A. Gottardo, Jenny Lee, M. L. Cortés, S. Franchoo, C. Santamaria, B. D. Linh, V. Lapoux, Norbert Pietralla, and A. Delbart

Subjects
Physics, Low energy, 010308 nuclear & particles physics, Excited state, 0103 physical sciences, Neutron, Atomic physics, 010306 general physics, Spectroscopy, 01 natural sciences, Spectral line
Abstract

ray transitions between low-spin states of the neutron-rich 84;86;88Ge were measured by means of in-flight -ray spectroscopy at 270 MeV/u. Excited 6+ 1 , 4+ 1;2 and 2+ 1;2 states of 84;86Ge and 4+ 1 and 2+ 1;2 states of 88Ge were observed. Furthermore a candidate for a 3+ 1 state of 86Ge was identified. This state plays a key role in the discussion of ground-state triaxiality of 86Ge, along with other features of its low-energy level scheme. A new region of triaxially deformed nuclei is proposed in the Ge isotopic chain.

Published
2017
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53. Cross section measurements in the $^{12}$C+$^{12}$C system

Author

S. Della Negra, Sergio Almaraz-Calderon, Oliver S. Kirsebom, B. Bucher, C. L. Jiang, R. V. F. Janssens, Anne Meyer, Rashi Talwar, X.D. Tang, John P. Greene, B. B. Back, M. Heine, G. Fruet, X. Fang, Fairouz Hammache, D. J. Henderson, S. A. Kuvin, P. Adsley, Catherine Deibel, M. Rudigier, Kalle Auranen, S. Zhu, S. Courtin, M. Albers, D. Bourgin, M. P. Carpenter, Martín Alcorta, D. Seweryniak, Daniel Santiago-Gonzalez, D. Montanari, F. Haas, B. P. Kay, Calem Hoffman, P. H. Regan, D. G. Jenkins, P. F. Bertone, J. Sethi, C. Stodel, Claudio Ugalde, A. Lefebvre-Schuhl, J. Lesrel, A. D. Ayangeakaa, Clayton Dickerson, K. E. Rehm, B. DiGiovine, L. Morris, N. de Séréville, R. C. Pardo, Melina Avila, T. Lauritsen, S. Bottoni, S. T. Marley, 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 d'Orsay (IPNO), 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), 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), 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), 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), and Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, 010308 nuclear & particles physics, QC1-999, Measure (physics), Aucun, chemistry.chemical_element, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Coincidence, law.invention, Nuclear physics, Ignition system, Cross section (physics), chemistry, 13. Climate action, law, 0103 physical sciences, Nuclear astrophysics, Nuclear fusion, 010306 general physics, Carbon
Abstract

International audience; The 12C+12C fusion reaction is one of the most important for nuclear astrophysics since it determines the carbon ignition in stellar environments. Two experiments which make use of the gamma-particle coincidence technique to measure the 12C+12C S-factors at deep sub barrier energies are discussed. Results are presented showing a decrease of the S-factor below Ec.m. = 3 MeV.

Published
2017
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54. Shape Evolution in Neutron-Rich Krypton Isotopes Beyond N=60 : First Spectroscopy of Kr98,100

Author

J.-Y. Roussé, Hiroyoshi Sakurai, A. Jungclaus, T. Motobayashi, A. Corsi, Jian Liu, A. Delbart, Victor Vaquero, A. Blazhev, R. Orlandi, C. Lizarazo, J. Libert, G. Authelet, F. Château, Toshiaki Ando, K. Moschner, Zhengyu Xu, N. Paul, Noritsugu Nakatsuka, J. M. Gheller, T. Arici, I. Stefan, C. Santamaria, Zi Hong Liu, V. Werner, T. Saito, Si-Ge Chen, Kathrin Wimmer, Zena Patel, P. A. Söderström, A. Obertelli, S. Nagamine, M. Górska, M. L. Cortés, Alison Bruce, M. Girod, A. Giganon, Raymond J. Carroll, B. Ding, Zs. Podolyák, B. D. Linh, V. Lapoux, Megumi Niikura, Tomohiro Uesaka, L. X. Chung, C. R. Nobs, F. Browne, A. Gottardo, Jenny Lee, P. Doornenbal, A. Gillibert, C. M. Shand, F. Flavigny, H. Baba, C. R. Nita, J.-P. Delaroche, S. Franchoo, Ryo Taniuchi, David Steppenbeck, M. Dewald, L. Olivier, D. Calvet, Tomás R. Rodríguez, Satoru Momiyama, M. Lettmann, and M. Rudigier

Subjects
Physics, Isotope, 010308 nuclear & particles physics, Nuclear Theory, General Physics and Astronomy, Isotopes of krypton, 01 natural sciences, Neutron number, 0103 physical sciences, Isotopes of zirconium, Neutron, Gamma spectroscopy, Atomic physics, Nuclear Experiment, 010306 general physics, Spectroscopy, Nucleon
Abstract

We report on the first γ-ray spectroscopy of low-lying states in neutron-rich 98,100Kr isotopes obtained from 99,101Rb(p,2p) reactions at ∼ 220 MeV/nucleon. A reduction of the 2+ 1 state energies beyond N = 60 demonstrates a significant increase of deformation, shifted in neutron number compared to the sharper transition observed in strontium and zirconium isotopes. State-of-theart beyond-mean-field calculations using the Gogny D1S interaction predict level energies in good agreement with experimental results. The identification of a low-lying (0+ 2 , 2+ 2 ) state in 98Kr provides the first experimental evidence of a competing configuration at low energy in neutron-rich krypton isotopes consistent with the oblate-prolate shape coexistence picture suggested by theory

Published
2017
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55. Conceptual design of the AGATA 1$\pi$ array at GANIL

Author

E. Clément, C. Michelagnoli, G. de France, H.J. Li, A. Lemasson, C. Barthe Dejean, M. Beuzard, P. Bougault, J. Cacitti, J.-L. Foucher, G. Fremont, P. Gangnant, J. Goupil, C. Houarner, M. Jean, A. Lefevre, L. Legeard, F. Legruel, C. Maugeais, L. Ménager, N. Ménard, H. Munoz, M. Ozille, B. Raine, J.A. Ropert, F. Saillant, C. Spitaels, M. Tripon, Ph. Vallerand, G. Voltolini, W. Korten, M.-D. Salsac, Ch. Theisen, M. Zielińska, T. Joannem, M. Karolak, M. Kebbiri, A. Lotode, R. Touzery, Ch. Walter, A. Korichi, J. Ljungvall, A. Lopez-Martens, D. Ralet, N. Dosme, X. Grave, N. Karkour, X. Lafay, E. Legay, I. Kojouharov, C. Domingo-Pardo, A. Gadea, R.M. Pérez-Vidal, J.V. Civera, B. Birkenbach, J. Eberth, H. Hess, L. Lewandowski, P. Reiter, A. Nannini, G. De Angelis, G. Jaworski, P. John, D.R. Napoli, J.J. Valiente-Dobón, D. Barrientos, D. Bortolato, G. Benzoni, A. Bracco, S. Brambilla, F. Camera, F.C.L. Crespi, S. Leoni, B. Million, A. Pullia, O. Wieland, D. Bazzacco, S.M. Lenzi, S. Lunardi, R. Menegazzo, D. Mengoni, F. Recchia, M. Bellato, R. Isocrate, F.J. Egea Canet, F. Didierjean, G. Duchêne, R. Baumann, M. Brucker, E. Dangelser, M. Filliger, H. Friedmann, G. Gaudiot, J.-N. Grapton, H. Kocher, C. Mathieu, M.-H. Sigward, D. Thomas, S. Veeramootoo, J. Dudouet, O. Stézowski, C. Aufranc, Y. Aubert, M. Labiche, J. Simpson, I. Burrows, P.J. Coleman-Smith, A. Grant, I.H. Lazarus, P.S. Morrall, V.F.E. Pucknell, A. Boston, D.S. Judson, N. Lalović, J. Nyberg, J. Collado, V. González, I. Kuti, B.M. Nyakó, A. Maj, M. Rudigier, 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), Département de Physique Nucléaire (ex SPhN) (DPHN), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, AGATA, 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), 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), Instituto de Fisica Corpuscular (IFIC), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC)-Universitat de València (UV), University of Cologne, Istituto Nazionale di Fisica Nucleare, Sezione di Firenze (INFN, Sezione di Firenze), Istituto Nazionale di Fisica Nucleare (INFN), INFN Laboratori Nazionali di Legnaro, Istituto Nazionale di Fisica Nucleare, Sezione di Milano (INFN), Istituto Nazionale di Fisica Nucleare, Sezione di Padova (INFN, Sezione di Padova), Institut Pluridisciplinaire Hubert Curien (IPHC), 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), 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), Institut de Physique Nucléaire d'Orsay (IPNO), Computational Science and Engineering Department [Daresbury] (STFC), Science & Technologie Facilities Council, University of Liverpool, Lund University [Lund], Uppsala University, Department of Electronic Engineering [Universitat Politecnica de Valencia], Universitat Politècnica de València (UPV), Hungarian Academy of Sciences (MTA), Institute of Physics, Polish Academy of Sciences, Polska Akademia Nauk = Polish Academy of Sciences (PAN), Department of Physics, University of Surrey, University of Surrey (UNIS), the EU FEDER funds, MINECO and Generalitat Valenciana, Spain, under the Grants FPA2014-57196-C5, PROMETEOII/2014/019, European Project: 262010,EC:FP7:INFRA,FP7-INFRASTRUCTURES-2010-1,ENSAR(2010), and European Project: 654002,H2020,H2020-INFRAIA-2014-2015,ENSAR2(2016)

Subjects
Nuclear and High Energy Physics, Plunger device, Physics::Instrumentation and Detectors, Astrophysics::High Energy Astrophysical Phenomena, Cyclotron, Scintillator, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Accelerator Physics and Instrumentation, Tracking (particle physics), 01 natural sciences, 7. Clean energy, law.invention, Nuclear physics, Conceptual design, law, 0103 physical sciences, PARIS LaBr3 detector, Neutron detection, Pulse shape analysis, AGATA spectrometer, 010306 general physics, Nuclear Experiment, Instrumentation, Physics, Spectrometer, VAMOS plus plus spectrometer, 010308 nuclear & particles physics, Detector, FATIMA LaBr3 detector, Acceleratorfysik och instrumentering, DIAMANT detector, NEDA detector, Author Keywords:AGATA spectrometer, Physics::Accelerator Physics, AGATA, gamma-ray tracking, GANIL facility
Abstract

The Advanced GAmma Tracking Array (AGATA) has been installed at the GANIL facility, Caen-France. This setup exploits the stable and radioactive heavy-ions beams delivered by the cyclotron accelerator complex of GANIL. Additionally, it benefits from a large palette of ancillary detectors and spectrometers to address in-beam γ-ray spectroscopy of exotic nuclei. The set-up has been designed to couple AGATA with a magnetic spectrometer, charged-particle and neutron detectors, scintillators for the detection of high-energy γ rays and other devices such as a plunger to measure nuclear lifetimes. In this paper, the design and the mechanical characteristics of the set-up are described. Based on simulations, expected performances of the AGATA l π array are presented. Title in WoS: Conceptual design of the AGATA 1 pi array at GANIL

Published
2017
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56. γ-ray spectroscopy of low-lying excited states and shape competition inOs194

Author

S. Toma, R. Mărginean, Raymond J. Carroll, Zs. Podolyák, A. Turturica, L. Stan, T. Daniel, C. Sotty, C. R. Nita, R. Suvaila, L. A. Gurgi, C. Costache, P. H. Regan, N. Marginean, M. Rudigier, T. Berry, A. Olacel, Alin Titus Serban, A. Oprea, V. Werner, Kosuke Nomura, S. Kisyov, R. E. Mihai, and M. Boromiza

Subjects
Physics, Isotope, 010308 nuclear & particles physics, Yrast, Nuclear Theory, 01 natural sciences, medicine.anatomical_structure, Neutron number, Excited state, 0103 physical sciences, Quadrupole, medicine, Atomic physics, Nuclear Experiment, 010306 general physics, Spectroscopy, Nucleus, Beam (structure)
Abstract

The properties of excited states in the neutron-rich nucleus 194Os have been investigated using the 192Os(18O,16O)194Os reaction with an 80 MeV beam provided by the IFIN-HH Laboratory, Bucharest. Discrete γ -ray decays from excited states have been measured using the hybrid HPGe-LaBr3(Ce) array RoSPHERE. The current work identifies a number of previously unreported low-lying nonyrast states in 194Os as well as the first measurement of the half-life of the yrast 2+ state of 302(50) ps. This is equivalent to a B(E2 : 2+ → 0+) = 45(16) W.u. and intrinsic quadrupole deformation of βeff = 0.14(1). The experimental results are compared with Hartree-Fock-Bogoliubov–interacting-boson-model calculations and are consistent with a reduction in a quadrupole collectivity in Os isotopes with increasing neutron number.

Published
2017
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57. Are There Signatures of Harmonic Oscillator Shells Far from Stability? First Spectroscopy of Zr110

Author

A. Giganon, M. Girod, T. Arici, J.-Y. Roussé, S. Franchoo, Toshiaki Ando, Ryo Taniuchi, A. Jungclaus, B. Ding, Si-Ge Chen, Jian Liu, P. A. Söderström, A. Gillibert, V. Lapoux, Zena Patel, B. D. Linh, Hiroyoshi Sakurai, C. M. Shand, A. Blazhev, C. R. Nita, A. Gottardo, Jenny Lee, T. Motobayashi, J. Libert, B. Bally, F. Château, A. Corsi, A. Delbart, H. Baba, F. Browne, Alison Bruce, Tomoaki Togashi, Megumi Niikura, Zhengyu Xu, J.-P. Delaroche, Tomohiro Uesaka, Tomás R. Rodríguez, P. Doornenbal, M. Rudigier, C. Santamaria, A. Obertelli, T. Saito, Satoru Momiyama, R. Orlandi, M. Lettmann, M. Górska, F. Flavigny, N. Paul, Noritsugu Nakatsuka, M. L. Cortés, Zi Hong Liu, V. Werner, Raymond J. Carroll, V. Vaquero, Paul-Henri Heenen, Zs. Podolyák, I. Stefan, Michaël Bender, C. Lizarazo, L. X. Chung, Yusuke Tsunoda, C. R. Nobs, K. Moschner, G. Authelet, J. M. Gheller, Kathrin Wimmer, David Steppenbeck, Takaharu Otsuka, M. Dewald, D. Calvet, Noritaka Shimizu, L. Olivier, and S. Nagamine

Subjects
Physics, Proton, 010308 nuclear & particles physics, General Physics and Astronomy, 01 natural sciences, 7. Clean energy, 0103 physical sciences, Isotopes of zirconium, Rigid rotor, Atomic physics, 010306 general physics, Nucleon, Ground state, Spectroscopy, Harmonic oscillator, Excitation
Abstract

The first measurement of the low-lying states of the neutron-rich 110 Zr and 112 Mo was performed via in-beam γ -ray spectroscopy after one proton removal on hydrogen at ∼ 200 MeV / nucleon . The 2 + 1 excitation energies were found at 185(11) keV in 110 Zr , and 235(7) keV in 112 Mo , while the R 42 = E ( 4 + 1 ) / E ( 2 + 1 ) ratios are 3.1(2), close to the rigid rotor value, and 2.7(1), respectively. These results are compared to modern energy density functional based configuration mixing models using Gogny and Skyrme effective interactions. We conclude that first levels of 110 Zr exhibit a rotational behavior, in agreement with previous observations of lighter zirconium isotopes as well as with the most advanced Monte Carlo shell model predictions. The data, therefore, do not support a harmonic oscillator shell stabilization scenario at Z = 40 and N = 70 . The present data also invalidate predictions for a tetrahedral ground state symmetry in 110 Zr .

Published
2017
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58. Fast timing measurement using an labr3(Ce) scintillator detector array coupled with gammasphere

Author

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

Subjects
Physics, Fission products, 010308 nuclear & particles physics, Fission, General Physics and Astronomy, Radiation, Nanosecond, Scintillator, 01 natural sciences, Nuclear physics, Data acquisition, Picosecond, 0103 physical sciences, Gammasphere, Física nuclear, 010306 general physics
Abstract

A fast-timing experiment was performed at the Argonne National Laboratory in December 2015 and January 2016, measuring decay radiation of fission products from a Cf-252 fission source. Details of the set-up, integration with Digital Gammasphere, and the data acquisition system are presented. The timing performance of the set-up, capable of measuring lifetimes from the nanosecond region down to tens of picoseconds, is discussed. First preliminary results from the fast-timing analysis of the fission fragment data are presented.

Published
2017
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59. Evolution of collectivity near mid-shell from excited-state lifetime measurements in rare earth nuclei

Author

Andreas Martin Heinz, Deniz Savran, G. Ilie, Elizabeth Williams, D. Radeck, J.-M. Régis, R. F. Casten, M. Rudigier, Z. Berant, V. Anagnostatou, Mallory Smith, V. Werner, M. Bonett-Matiz, J. Jolie, R. B. Cakirli, N. Cooper, Tan Ahn, and M. Elvers

Subjects
Physics, Rare earth nuclei, Scintillation, Valence (chemistry), Isotope, 010308 nuclear & particles physics, Rare earth, 01 natural sciences, Excited state, 0103 physical sciences, Atomic physics, Nuclear Experiment, 010306 general physics, Excitation
Abstract

The B(E2) excitation strength of the first excited 2(+) state in even-even nuclei should directly correlate with the size of the valence space and maximize at mid-shell. A previously found saturation of B(E2) strengths in well-deformed rotors at mid-shell is tested through high-precision measurements of the lifetimes of the lowest-lying 2(+) states of the Hf-168 and W-174 rare earth isotopes. Measurements were performed using fast LaBr3 scintillation detectors. Combined with the recently remeasured B(E2; 2(1)(+) -> 0(1)(+)) values for Hf and W isotopes the new data remove discrepancies observed in the differentials of B(E2) values for these isotopes.

Published
2016
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60. The time-walk of analog constant fraction discriminators using very fast scintillator detectors with linear and non-linear energy response

Author

Gheorghe Pascovici, N. Warr, M. Rudigier, J. Jolie, C. Fransen, A. Blazhev, and J.-M. Régis

Subjects
Physics, Nuclear and High Energy Physics, Photomultiplier, business.industry, Detector, Centroid, Constant fraction discriminator, Scintillator, Optics, Amplitude, Coincident, Constant (mathematics), business, Instrumentation
Abstract

The electronic γ–γ fast timing technique allows for direct nuclear lifetime determination down to the few picoseconds region by measuring the time difference between two coincident γ-ray transitions. Using high resolution ultra-fast LaBr3(Ce) scintillator detectors in combination with the recently developed mirror symmetric centroid difference method, nuclear lifetimes are measured with a time resolving power of around 5 ps. The essence of the method is to calibrate the energy dependent position (centroid) of the prompt response function of the setup which is obtained for simultaneously occurring events. This time-walk of the prompt response function induced by the analog constant fraction discriminator has been determined by systematic measurements using different photomultiplier tubes and timing adjustments of the constant fraction discriminator. We propose a universal calibration function which describes the time-walk or the combined γ–γ time-walk characteristics, respectively, for either a linear or a non-linear amplitude versus energy dependency of the scintillator detector output pulses.

Published
2012
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61. Lifetime of the first excited state in 172W and 178W

Author

K. O. Zell, J.-M. Régis, M. Rudigier, J. Jolie, and C. Fransen

Subjects
Physics, Rare earth nuclei, Nuclear reaction, Nuclear and High Energy Physics, chemistry, Isotope, Spectrometer, Excited state, chemistry.chemical_element, Interacting boson model, Tungsten, Atomic physics, Electron spectroscopy
Abstract

The lifetime of the first excited 2 + state in 172W and 178W has been measured in fast timing experiments using the Cologne Double Orange Spectrometer for conversion electron spectroscopy. The B ( E 2 , 2 1 + → 0 1 + ) values of the isotopes 170–178W are compared to calculations in the Interacting Boson Model (IBM) employing the consistent Q formalism. An analysis of the B ( E 2 ) value systematics in the rare earth nuclei around mass A = 170 using the N p N n -scheme shows signatures of a structural change in the tungsten isotopes which is not reflected in the energy systematics.

Published
2010
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62. The mirror symmetric centroid difference method for picosecond lifetime measurements via γ–γ coincidences using very fast LaBr3(Ce) scintillator detectors

Author

M. Rudigier, Gheorghe Pascovici, J. Jolie, and J.-M. Régis

Subjects
Physics, Nuclear and High Energy Physics, Range (particle radiation), Physics::Instrumentation and Detectors, business.industry, Detector, Centroid, Scintillator, Spectral line, Optics, Picosecond, Excited state, business, Instrumentation, Energy (signal processing)
Abstract

The ultra-fast timing technique was introduced in the 1980s and is capable of measuring picosecond lifetimes of nuclear excited states with about 3 ps accuracy. Very fast scintillator detectors are connected to an electronic timing circuit and detector vs. detector time spectra are analyzed by means of the centroid shift method. The very good 3% energy resolution of the nowadays available LaBr3(Ce) scintillator detectors for γ -rays has made possible an extension of the well-established fast timing technique. The energy dependent fast timing characteristics or the prompt curve, respectively, of the LaBr3(Ce) scintillator detector has been measured using a standard 152Eu γ -ray source. For any energy combination in the range of 200 keV E γ 1500 keV , the γ – γ fast timing characteristics is calibrated as a function of energy with an accuracy of 2–4 ps. An extension of the centroid shift method providing very attractive features for picosecond lifetime measurements is presented. The mirror symmetric centroid difference method takes advantage of the symmetry obtained when performing γ – γ lifetime measurements using a pair of almost identical very fast scintillator detectors. In particular cases, the use of the mirror symmetric centroid difference method also allows the direct determination of picosecond lifetimes, hence without the need of calibrating the prompt curve.

Published
2010
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63. Sub-nanosecond lifetime measurements using the Double Orange Spectrometer at the cologne 10MV Tandem accelerator

Author

L. Steinert, N. Braun, Gheorghe Pascovici, M. Rudigier, S. Thiel, G. Breuer, J. Jolie, N. Warr, S. Christen, C. Bernards, Ch. Fransen, T. Meersschaut, K. O. Zell, J.-M. Régis, Stefan Heinze, and T. Materna

Subjects
Physics, Nuclear and High Energy Physics, Electron spectrometer, Spectrometer, business.industry, Detector, Nanosecond, Scintillator, Electron spectroscopy, Nuclear physics, Optics, Beamline, Excited state, Nuclear Experiment, business, Instrumentation
Abstract

Conversion electron spectroscopy constitutes an important tool in nuclear structure physics. A high efficiency iron-free Orange type electron spectrometer with an energy resolution of 1–2% has been installed at a beam line of the Cologne 10 MV FN Tandem Van-de-Graaff accelerator for in-beam studies of conversion electrons. In combination with a γ -ray detector array, high efficiency e - – γ -coincidences can be performed. The newly developed very fast LaBr 3 ( Ce ) scintillator detector with an energy resolution of about 4% makes it also possible to use e - – γ -coincidences for lifetime measurements of nuclear excited states. A second iron-free Orange spectrometer can be connected to perform e - – e - -coincidences. Because of the higher efficiency and the better energy resolution, the use of the Double Orange Spectrometer for lifetime measurements is more powerful. Lifetimes down to 100 ps and even less can be determined with an accuracy of about 10 ps. The working principle of the Orange spectrometer and the setup of the Double Orange Spectrometer are described. The performances are illustrated by examples of in-beam experiments with a main focus on high precision lifetime measurements.

Published
2009
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64. Relativistic Coulomb excitation of Kr 88

Author

S. Brambilla, A. Corsi, B. S. Nara Singh, F. Camera, Oliver Wieland, Norbert Pietralla, Joakim Cederkäll, Agnese Giaz, S. Pietri, M. Danchev, P. Bednarczyk, N. Braun, H. Schaffner, F. Ameil, A. Blazhev, N. Mǎrginean, Pavel Golubev, T. Habermann, C. Nociforo, N. Warr, K. Sieja, M. Reese, H. J. Wollersheim, K. Moschner, P. Reiter, Jan Taprogge, M. Rudigier, A. Prochazka, T. Möller, T. Thomas, Helmut Weick, M. A. Bentley, Robert Hoischen, P. Boutachkov, T. Sava, Alejandro Algora, Claes Fahlander, Anna Wendt, L. Scruton, M. Hackstein, F. Naqvi, J. Jolie, I. Kojouharov, Douglas D. DiJulio, Dirk Rudolph, J. Grebosz, E. Merchan, N. Kurz, Zs. Podolyák, J. Gerl, M. Górska, 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 National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), and Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Nuclear Theory, Nuclear structure, State (functional analysis), Coulomb excitation, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Nuclear physics, gamma-ray spectroscopy, Subatomic Physics, relativistic Coulomb excitation, nuclear structure, 0103 physical sciences, Gamma spectroscopy, Atomic physics, Interacting boson model, Nuclear Experiment, 010306 general physics
Abstract

International audience; To investigate the systematics of mixed-symmetry states in N=52 isotones, a relativistic Coulomb excitation experiment was performed during the PreSPEC campaign at the GSI Helmholtzzentrum für Schwerionenforschung to determine E2 transition strengths to 2+ states of the radioactive nucleus $^{88}$Kr. Absolute transition rates could be measured towards the first and third 2+ states. For the latter a mixed-symmetry character is suggested on the basis of the indication for a strong M1 transition to the fully symmetric 21+ state, extending the knowledge of the N=52 isotones below Z=40. A comparison with the proton-neutron interacting boson model and shell-model predictions is made and supports the assignment.

Published
2016
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65. Erratum: Evidence for a Smooth Onset of Deformation in the Neutron-Rich Kr Isotopes [Phys. Rev. Lett.108, 062701 (2012)]

Author

C. Fransen, Takaharu Otsuka, C. Bauer, M. Kowalczyk, P. Reiter, N. Warr, G. S. Simpson, R. Krücken, S. Das Gupta, M. Rudigier, Jonathan Butterworth, P. Van Duppen, C. Bernards, H. De Witte, T. Davinson, T. Thomas, Iain Darby, Kentaro Nomura, B. Bastin, T. Kröll, D. G. Jenkins, D. Voulot, F. Wenander, E. Fiori, Marc Huyse, P. Thöle, Liam Gaffney, Georgi P. Georgiev, P. J. Napiorkowski, M. Hackstein, Stefan Heinze, R. Lutter, R. Wadsworth, J. Konki, Joakim Cederkäll, K. O. Zell, N. Marginean, Janne Pakarinen, D. Mücher, Marcus Scheck, J. M. Daugas, J. Litzinger, Roman Gernhäuser, M. Albers, J. Jolie, M. Zielińska, Susan Rigby, L. M. Robledo, D. Cline, A. Blazhev, M. Seidlitz, M. J. Vermeulen, V. Bildstein, B. S. Nara Singh, M. Pfeiffer, Pedro Sarriguren, B. Siebeck, D. M. Filipescu, Jan Diriken, C. Mihai, D. Radeck, L. Bettermann, K. Moschner, Herbert Hess, Kathrin Wimmer, M. Cappellazzo, R. R. Rodríguez-Guzmán, K. Nowak, and J. Van de Walle

Subjects
Physics, Nuclear physics, Isotope, General Physics and Astronomy, Neutron, Deformation (meteorology)
Published
2015
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66. Evolution ofE2transition strength in deformed hafnium isotopes from new measurements onHf172,Hf174, andHf176

Author

J.-M. Régis, S. Stegemann, M. Rudigier, K. O. Zell, Kosuke Nomura, R.-B. Gerst, J. Jolie, L. M. Robledo, N. Saed-Samii, A. Blazhev, N. Warr, R. R. Rodríguez-Guzmán, C. Fransen, and M. Dannhoff

Subjects
Physics, Nuclear and High Energy Physics, Isotope, chemistry.chemical_element, Coulomb excitation, Hafnium, symbols.namesake, chemistry, Picosecond, symbols, Interacting boson model, Atomic physics, Spectroscopy, Hamiltonian (quantum mechanics), Boson
Abstract

Background: The available data for $E2$ transition strengths in the region between neutron-deficient hafnium and platinum isotopes are far from complete. More and precise data are needed to enhance the picture of structure evolution in this region and to test state-of-the-art nuclear models. In a simple model, the maximum collectivity is expected at the middle of the major shell. However, for actual nuclei, particularly in heavy-mass regions, which should be highly complex, this picture may no longer be the case, and one should use a more realistic nuclear-structure model. We address this point by studying the spectroscopy of Hf as a representative case.Purpose: We remeasure the ${2}_{1}^{+}$ half-lives of $^{172,174,176}\mathrm{Hf}$, for which there is some disagreement in the literature. The main goal is to measure, for the first time, the half-lives of higher-lying states of the rotational band. The new results are compared to a theoretical calculation for absolute transition strengths.Method: The half-lives were measured using $\ensuremath{\gamma}\text{\ensuremath{-}}\ensuremath{\gamma}$ and conversion-electron-$\ensuremath{\gamma}$ delayed coincidences with the fast timing method. For the determination of half-lives in the picosecond region, the generalized centroid difference method was applied. For the theoretical calculation of the spectroscopic properties, the interacting boson model is employed, whose Hamiltonian is determined based on microscopic energy-density functional calculations.Results: The measured ${2}_{1}^{+}$ half-lives disagree with results from earlier $\ensuremath{\gamma}\text{\ensuremath{-}}\ensuremath{\gamma}$ fast timing measurements, but are in agreement with data from Coulomb excitation experiments and other methods. Half-lives of the ${4}_{1}^{+}$ and ${6}_{1}^{+}$ states were measured, as well as a lower limit for the ${8}_{1}^{+}$ states.Conclusions: This work shows the importance of a mass-dependent effective boson charge in the interacting boson model for the description of $E2$ transition rates in chains of nuclei. It encourages further studies of the microscopic origin of this mass dependence. New experimental values on transition rates in nuclei from neighboring isotopic chains could support these studies.

Published
2015
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67. Low-lying isomeric states in Ga80 from the β− decay of Zn80

Author

R. Lică, N. Mărginean, D. G. Ghiţă, H. Mach, L. M. Fraile, G. S. Simpson, A. Aprahamian, C. Bernards, J. A. Briz, B. Bucher, C. J. Chiara, Z. Dlouhý, I. Gheorghe, P. Hoff, J. Jolie, U. Köster, W. Kurcewicz, R. Mărginean, B. Olaizola, V. Paziy, J. M. Régis, M. Rudigier, T. Sava, M. Stănoiu, L. Stroe, and W. B. Walters

Subjects
Physics, Nuclear and High Energy Physics, medicine.anatomical_structure, Double beta decay, medicine, Observable, Atomic physics, Ground state, Nucleus, Beta decay, Excitation
Abstract

A new level scheme of 80Ga has been determined. This nucleus was populated following the β− decay of 80Zn at ISOLDE, CERN. The proposed level scheme is significantly different compared to the previously reported one and contains 26 levels up to 3.4 MeV in excitation energy. The present study establishes that the previously identified 1.9-s β− -decaying 6− isomer is the ground state of 80Ga and the 1.3-s β− -decaying 3− isomer lies at an excitation energy of 22.4 keV. A new isomeric level was identified at 707.8 keV and its half-life was measured to be 18.3(5) ns, allowing the 685.4-keV transition de-exciting this state to be assigned anM2 multipolarity. The newly measured spectroscopic observables are compared with shell-model calculations using the jj44bpn and JUN45 interactions.

Published
2014
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68. Fast-Timing Study in the 78Ni Region: β-Decay of 81Zn

Author

Z. Dlouhý, Brian Bucher, C. J. Chiara, B. Olaizola, R. Mărginean, J. M. Udías, N. Mărginean, P. Hoff, I. Gheorghe, L. M. Fraile, V. Paziy, M. Rudigier, Henryk Mach, J. Jolie, J. M. Régis, Gary Simpson, Ani Aprahamian, R. Lica, C. Bernards, D. Ghiţă, M. Stanoiu, T. Sava, W. Kurcewicz, Ulli Köster, W. B. Walters, L. Stroe, José Antonio Briz, Institut Laue-Langevin (ILL), ILL, Laboratoire de Physique Subatomique et de Cosmologie (LPSC), and Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS)

Subjects
Nuclear physics, Physics, Large Hadron Collider, medicine.anatomical_structure, [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], Excited state, medicine, Limit (mathematics), Nucleus
Abstract

International audience; The neutron-rich nucleus 81Ga was populated from the β-decay of 81Zn produced at the ISOLDE (CERN) facility. The analysis of β-gated γ-ray singles and γ-γ coincidences permits to extend significantly the level scheme of 81Ga as well as to provide a new half-life for 81Zn. A preliminary upper limit was obtained for the half-life of the first excited state in 81Ga.

Published
2014
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69. Delayedγ-ray and conversion-electron spectroscopy ofA=97fission fragments

Author

N. Pillet, J.-M. Régis, Ulli Köster, C. Fransen, T. Materna, J. Le Bloas, T. Thomas, W. Rother, D. Wilmsen, M. Hackstein, M. Ramdhane, N. Warr, M. Pfeiffer, M. Rudigier, T. Malkiewicz, Guillaume Gey, A. Blazhev, Gary Simpson, J. M. Daugas, and J. Jolie

Subjects
Physics, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Fission, 0103 physical sciences, Radiochemistry, 010306 general physics, 01 natural sciences, Electron spectroscopy
Published
2013
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71. EVOLUTION OF NUCLEAR DEFORMATION IN NEUTRON-RICH <font>Kr</font> ISOTOPES

Author

P. Reiter, T. Thomas, P. Thoele, Jan Diriken, A. Blazhev, H. Dewitte, M. Pfeiffer, C. Fransen, K. O. Zell, B. Siebeck, N. Marginean, K. Moschner, M. Albers, J. Jolie, M. Cappellazzo, M. Hackstein, D. Radeck, M. Rudigier, D. Mücher, L. Bettermann, P. Van Duppen, M. Seidlitz, N. Warr, B. Bastin, and C. Bernards

Subjects
Nuclear physics, Physics, Isotope, Nuclear structure, Neutron, Coulomb excitation, Deformation (meteorology)
Published
2013
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72. Recent Results from Lohengrin on Fission Yields and Related Decay Properties

Author

C. Sage, Alain Letourneau, C. Amouroux, W. Urban, S. Panebianco, M. Rudigier, J.-M. Régis, Olivier Serot, L. Mathieu, Adrien Bidaud, F. Martin, N. Capellan, U. Koester, H. Faust, S. Chabod, A. Ebran, Olivier Litaize, T. Materna, Grégoire Kessedjian, Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS), Institut Laue-Langevin (ILL), ILL, Aval du cycle et Energie Nucléaire (ACEN), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and Vernay, Emmanuelle

Subjects
Physics, Nuclear and High Energy Physics, Fission products, Nuclear fission product, Cluster decay, [PHYS.NEXP] Physics [physics]/Nuclear Experiment [nucl-ex], Fission, Neutron emission, Fission product yield, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 7. Clean energy, Nuclear physics, Neutron cross section, Neutron, Nuclear Experiment, ComputingMilieux_MISCELLANEOUS
Abstract

communication - http://hal.in2p3.fr/in2p3-00797284; International audience; The Lohengrin mass spectrometer is one of the 40 instruments built around the reactor of the Institute Laue-Langevin (France) which delivers a very intense thermal neutron flux. Usually, Lohengrin was combined with a high-resolution ionization chamber in order to obtain good nuclear charge discrimination within a mass line, yielding an accurate isotopic yield determination. Unfortunately, this experimental procedure can only be applied for fission products with a nuclear charge less than about 42, i.e. in the light fission fragment region. Since 2008, a large collaboration has started with the aim of studying various fission aspects, mainly in the heavy fragment region. For that, a new experimental setup which allows isotopic identification by γ-ray spectrometry has been developed and validated. This technique was applied on the 239Pu(nth,f) reaction where about 65 fission product yields were measured with an uncertainty that has been reduced on average by a factor of 2 compared with what was that previously available in nuclear data libraries. The same γ-ray spectrometric technique is currently being applied to the study of the 233U(nth,f) reaction. Our aim is to deduce charge and mass distributions of the fission products and to complete the experimental data that exist mainly for light fission fragments. The measurement of 41 mass yields from the 241Am(2nth,f) reaction has been also performed. In addition to these activities on fission yield measurements, various new nanosecond isomers were discovered. Their presence can be revealed from a strong deformed ionic charge distribution compared to a 'normal' Gaussian shape. Finally, a new neutron long-counter detector designed to have a detection efficiency independent of the detected neutron energy has been built. Combining this neutron device with a Germanium detector and a beta-ray detector array allowed us to measure the beta-delayed neutron emission probability Pn of some important fission products for reactor applications.

Published
2013
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73. Sub-barrier fusion cross section measurements with STELLA

Author

Oliver S. Kirsebom, G. Heitz, G. Fruet, F. Haas, C. Stodel, D. G. Jenkins, D. Montanari, P. H. Regan, L. Morris, S. Della Negra, M. Krauth, M. Richer, M. Rudigier, M. Heine, P. Adsley, F. Hammache, P. Dené, S. Courtin, J. Lesrel, A. Meyer, C. Beck, N. de Séréville, Institut Pluridisciplinaire Hubert Curien (IPHC), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Université de Strasbourg (UNISTRA), Institut de Physique Nucléaire d'Orsay (IPNO), 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 National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), 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), 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), and 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)

Subjects
Physics, Fusion, 010308 nuclear & particles physics, QC1-999, Detector, Aucun, Stella (software), [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, 7. Clean energy, Coincidence, Nuclear physics, Cross section (physics), 0103 physical sciences, Background suppression, Heavy ion, 010306 general physics
Abstract

International audience; The experimental setup STELLA (STELlar LAboratory) is designed for the measurement of deep sub-barrier light heavy ion fusion cross sections. For background suppression the γ-particle coincidence technique is used. In this project, LaBr3 detectors from the UK FATIMA (FAst TIMing Array) collaboration are combined with annular silicon strip detectors customized at IPHC-CNRS, Strasbourg, and the setup is located at Andromède, IPN, Orsay. The commissioning of the experimental approach as well as a sub-barrier 12C +12C → 24Mg∗ cross section measurement campaign are carried out.

Published
2017
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74. Shape dynamics in neutron-rich Kr isotopes: Coulomb excitation of 92Kr, 94Kr and 96Kr

Author

Jan Diriken, R. Krücken, Fredrik Wenander, D. Cline, T. Kröll, B. S. Nara Singh, C. Bauer, M. Zielińska, D. Radeck, K. Moschner, M. Seidlitz, C. Fransen, L. Bettermann, Stefan Heinze, T. Davinson, Mark Huyse, A. Blazhev, G. S. Simpson, R. Wadsworth, H. De Witte, M. Pfeiffer, Herbert Hess, P. Reiter, N. Warr, Iain Darby, Kathrin Wimmer, R. Gernhäuser, M. Rudigier, M. Vermeulen, B. Bastin, Kosuke Nomura, D. M. Filipescu, J. Van de Walle, M. Cappellazzo, Georgi P. Georgiev, R. R. Rodríguez-Guzmán, Joakim Cederkäll, D. G. Jenkins, D. Mücher, K. Nowak, M. Hackstein, R. Lutter, T. Thomas, C. Mihai, K. O. Zell, P. Thöle, P. J. Napiorkowski, J. Litzinger, P. Van Duppen, Vinzenz Bildstein, M. Kowalczyk, S. Das Gupta, D. Voulot, Jonathan Butterworth, J. M. Daugas, Liam Gaffney, M. Albers, J. Jolie, L. M. Robledo, Joonas Konki, B. Siebeck, E. Fiori, Susan Rigby, N. Marginean, Janne Pakarinen, Marcus Scheck, C. Bernards, DAM Île-de-France (DAM/DIF), Direction des Applications Militaires (DAM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), CSNSM SNO, Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse (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)-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)-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), Laboratoire de Physique Subatomique et de Cosmologie (LPSC), and Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS)

Subjects
Nuclear reaction, Physics, Nuclear and High Energy Physics, Large Hadron Collider, ta114, [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], 010308 nuclear & particles physics, Projectile, Coulomb excitation, 01 natural sciences, 7. Clean energy, Nuclear physics, Matrix (mathematics), Excited state, 0103 physical sciences, Physics::Accelerator Physics, Neutron, Interacting boson model, Atomic physics, Nuclear Experiment, 010306 general physics
Abstract

We report on the study of excited states in 92,94,96Kr populated via projectile Coulomb excitation at safe energies. The radioactive ion beams at energies of 2.85 MeV/u were delivered by the REX-ISOLDE facility at CERN and impinged on self-supporting 194,196Pt targets. The emitted γ -rays were detected by the Miniball detector-array. A detailed description of the experimental techniques used for extracting diagonal and transitional matrix elements and of the theoretical framework is given. The present experiment reveals the moderate evolution of the collective structure in the considered neutron-rich Kr isotopic chain, which is supported by the interacting boson model combined with the self-consistent mean-field method using a microscopic Gogny energy-density functional. The theory also suggests possible shape coexistence in the exotic nucleus 96Kr. ispartof: Nuclear Physics A vol:899 pages:1-28 status: published

Published
2013
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75. Structure of [sup 81]Ga populated from the β− decay of [sup 81]Zn

Author

T. Sava, M. Stanoiu, P. Hoff, I. Gheorghe, Z. Dlouhy, W. B. Walters, H. Mach, R. Lica, José Antonio Briz, B. Bucher, G. S. Simpson, R. Mărginean, C. Bernards, L. Stroe, C. J. Chiara, V. Paziy, L. M. Fraile, J. M. Udías, N. Mărginean, B. Olaizola, A. Aprahamian, W. Kurcewicz, J. M. Régis, M. Rudigier, Ulli Köster, and D. Ghita

Subjects
Physics, Nuclear physics, Decay scheme, Large Hadron Collider, Nuclear structure, Nuclear shell model, Half-life, Gamma spectroscopy, Nuclear Experiment, Beta decay, Radioactive decay
Abstract

We report on the results of the β-decay of 81Zn. The experiment was performed at the CERN ISOLDE facility in the framework of a systematic ultra-fast timing investigation of neutron-rich nuclei populated in the decay of Zn. The present analysis included β-gated γ-ray singles and γ-γ coincidences from the decay of 81Zn to 81Ga and leads to a new and much more extensive level scheme of 81Ga. A new half-life of 81Zn is provided.

Published
2013
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76. Studies of pear-shaped nuclei using accelerated radioactive beams

Author

Mark Huyse, Jan Diriken, D. Radeck, P. J. Napiorkowski, D. T. Joss, S. Bönig, A. B. Hayes, L. M. Robledo, Joonas Konki, C. Y. Wu, D. G. Jenkins, K. Reynders, A. Herzan, M. J. Vermeulen, N. Kesteloot, Fredrik Wenander, N. Bree, P. A. Butler, K. Moschner, Timothy Chupp, Janne Pakarinen, P. Reiter, M. Seidlitz, K. Wrzosek-Lipska, M. Albers, S. Sambi, Kathrin Wimmer, D. Voulot, M. von Schmid, A. Blazhev, D. Cline, Liam Gaffney, C. Bauer, E. Kwan, M. Pfeiffer, M. Kowalczyk, Th. Kröll, P. Thoele, M. Rudigier, Joakim Cederkäll, B. Siebeck, Thomas Davinson, T. Grahn, Thierry Stora, Thomas Elias Cocolios, Marcus Scheck, R. Lutter, Susan Rigby, P. Van Duppen, M. Zielinska, N. Warr, B. Bastin, H. De Witte, 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 de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, and 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)

Subjects
Physics, Multidisciplinary, Isotope, ta114, 010308 nuclear & particles physics, Nuclear Theory, Nuclear structure, Coulomb excitation, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Nuclear physics, 0103 physical sciences, Atomic nucleus, Quadrupole, Physics::Accelerator Physics, Neutron, Nuclide, Physics::Atomic Physics, Atomic physics, 010306 general physics, Nucleon, Nuclear Experiment
Abstract

There is strong circumstantial evidence that certain heavy, unstable atomic nuclei are ‘octupole deformed’, that is, distorted into a pear shape. This contrasts with the more prevalent rugby-ball shape of nuclei with reflection-symmetric, quadrupole deformations. The elusive octupole deformed nuclei are of importance for nuclear structure theory, and also in searches for physics beyond the standard model; any measurable electric-dipole moment (a signature of the latter) is expected to be amplified in such nuclei. Here we determine electric octupole transition strengths (a direct measure of octupole correlations) for short-lived isotopes of radon and radium. Coulomb excitation experiments were performed using accelerated beams of heavy, radioactive ions. Our data on 220Rn and 224Ra show clear evidence for stronger octupole deformation in the latter. The results enable discrimination between differing theoretical approaches to octupole correlations, and help to constrain suitable candidates for experimental studies of atomic electric-dipole moments that might reveal extensions to the standard model. An experimental study of certain short-lived isotopes of radon and radium has found clear octupole deformation in the nuclei of the latter — that is, these nuclei are pear-shaped; the results enable discrimination between differing theoretical approaches to octupole correlations. The atomic nucleus is a many-body quantum system with a shape determined by the number of nucleons that it contains and the interactions between them. Most of the several thousand known stable and radioactive atomic nuclei, with differing numbers of protons and neutrons, are spherical or rugby-ball shaped. But there is circumstantial evidence that some heavy, unstable nuclides are distorted into a pear shape through the phenomenon of octupole deformation. Samples of these rare atomic species can be accelerated to 8% of the speed of light in the REX-ISOLDE facility at CERN, and now Coulomb excitation experiments on beams of the short-lived isotopes radium-224 and radon-220 have demonstrated clear octupole deformation in the former. The results make it possible to discriminate between the various theoretical models of octupole-deformed nuclei, and are also relevant to the pursuit of physics beyond the Standard Model.

Published
2013
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77. Gamma Efficiency Simulations towards Coincidence Measurements for Fusion Cross Sections

Author

D. Symochko, M. Heine, L. Morris, D. Montanari, P. H. Regan, G. Fruet, S. Courtin, D. G. Jenkins, and M. Rudigier

Subjects
Physics, History, 010308 nuclear & particles physics, business.industry, Astrophysics::High Energy Astrophysical Phenomena, Detector, Monte Carlo method, Aucun, Gamma ray, Measure (physics), 01 natural sciences, Charged particle, Coincidence, 030218 nuclear medicine & medical imaging, Computer Science Applications, Education, Computational physics, 03 medical and health sciences, 0302 clinical medicine, Optics, Coincident, 0103 physical sciences, Calibration, business
Abstract

With the experimental station STELLA (STELlar LAboratory) we will measure fusion cross sections of astrophysical relevance making use of the coincident detection of charged particles and gamma rays for background reduction. For the measurement of gamma rays from the de-excitation of fusion products a compact array of 36 UK FATIMA LaBr3 detectors is designed based on efficiency studies with Geant4. The photo peak efficiency in the region of interest compares to other gamma detection systems used in this field. The features of the internal decay of 138La is used in a background study to obtain an online calibration of the gamma detectors. Background data are fit to the Monte Carlo model of the self activity assuming crude exponential behavior of external background. Accuracy in the region of interest is of the order of some keV in this first study.

Published
2016
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78. Applications of LaBr3(Ce) Gamma-ray Spectrometer Arrays for Nuclear Spectroscopy and Radionuclide Assay

Author

S M Judge, N Marginean, A.K. Pearce, Steven Bell, Giuseppe Lorusso, Zsolt Podolyak, R Marginean, L. A. Gurgi, P. H. Regan, S. Kisyov, Sean Collins, T. Daniel, R. Shearman, and M. Rudigier

Subjects
History, Radionuclide, Nuclear fuel, 010308 nuclear & particles physics, Chemistry, Gamma ray spectrometer, Scintillator, 01 natural sciences, Computer Science Applications, Education, Nuclear physics, 0103 physical sciences, Nuclear spectroscopy, Gammasphere, 010306 general physics, National laboratory, Spectroscopy
Abstract

An overview of the use of discrete energy gamma-ray detectors based on cerium- doped LaBr3 scintillators for use in nuclear spectroscopy is presented. This review includes recent applications of such detectors in mixed, 'hybrid' gamma-ray coincidence detection arrays such ROSPHERE at IFIN-HH, Bucharest; EXILL+FATIMA at ILL Grenoble, France; GAMMASPHERE+FATIMA at Argonne National Laboratory, USA; FATIMA + EURICA, at RIKEN, Japan; and the National Nuclear Array (NANA) at the UK's National Physical Laboratory. This conference paper highlights the capabilities and limitations of using these sub-nanosecond 'fast-timing', medium-resolution gamma-ray detectors for both nuclear structure research and radionuclide standardisation. Potential future application of such coincidence scintillator arrays in measurements of civilian nuclear fuel waste evaluation and assay is demonstrated using coincidence spectroscopy of a mixed 134,7Cs source.

Published
2016
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79. Erratum: Evidence for a Smooth Onset of Deformation in the Neutron-Rich Kr Isotopes [Phys. Rev. Lett.108, 062701 (2012)]

Author

Stefan Heinze, Herbert Hess, J. M. Daugas, P. Reiter, J. Litzinger, G. Georgiev, L. M. Robledo, C. Fransen, Joonas Konki, Kathrin Wimmer, Mark Huyse, M. Cappellazzo, G. S. Simpson, T. Davinson, T. Thomas, Kentaro Nomura, M. Pfeiffer, T. Kröll, M. Rudigier, D. Voulot, D. Cline, K. Nowak, Liam Gaffney, J. Van de Walle, A. Blazhev, R. Lutter, P. J. Napiorkowski, C. Bauer, Roman Gernhäuser, K. O. Zell, B. Bastin, Marcus Scheck, B. Siebeck, E. Fiori, Iain Darby, D. G. Jenkins, D. Radeck, L. Bettermann, M. Albers, K. Moschner, J. Jolie, Jonathan Butterworth, M. Kowalczyk, M. Vermeulen, R. Krücken, Fredrik Wenander, Susan Rigby, S. Das Gupta, Joakim Cederkäll, M. Hackstein, H. De Witte, N. Marginean, Janne Pakarinen, Takaharu Otsuka, R. R. Rodríguez-Guzmán, N. Warr, P. Thöle, M. Seidlitz, R. Wadsworth, M. Zielinska, D. Mücher, Pedro Sarriguren, C. Mihai, P. Van Duppen, C. Bernards, Vinzenz Bildstein, Jan Diriken, B. S. Nara Singh, and D. M. Filipescu

Subjects
Nuclear physics, Physics, Isotope, General Physics and Astronomy, Neutron, Coulomb excitation, Deformation (meteorology)
Published
2012
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80. High-precision excited state lifetime measurements in rare earth nuclei using LaBr3(Ce) detectors

Author

Elizabeth Williams, Andreas Martin Heinz, D. Radeck, J.-M. Régis, Z. Berant, Mallory Smith, Michael Bunce, N. Cooper, M. Rudigier, V. Werner, G. Ilie, Deniz Savran, J. Jolie, M. Bonett-Matiz, V. Anagnostatou, Tan Ahn, and M. Elvers

Subjects
Physics, Background subtraction, Scintillation, Physics beyond the Standard Model, Excited state, QC1-999, Resolution (electron density), Detector, Nuclear structure, Astrophysics, Order of magnitude, Computational physics
Abstract

To study how collective nuclear structure evolves towards mid-shell and test next-generation LaBr3 (Ce) scintillation detectors, measurements of the lifetimes of 21 + states in 168 Hf and 174 W were conducted at the Wright Nuclear Structure Laboratory. Preliminary results indicate that the excellent time and energy resolution of LaBr3 detectors make them well suited to fast timing measurements, allowing for improved background subtraction and peak resolution in comparison to BaF2 detectors. Preliminary analysis shows an order of magnitude reduction in the statistical error of the 2+ lifetimes in comparison to literature values for both nuclei. In the case of 174 W, a substantial reduction of the observed lifetime hints at the possibility of new physics in the region.

Published
2012

81. Evidence for a Smooth Onset of Deformation in the Neutron-Rich Kr Isotopes

Author

C. Bernards, Jan Diriken, M. Pfeiffer, K. Moschner, P. Reiter, M. Rudigier, H. De Witte, Jonathan Butterworth, J. M. Daugas, D. Voulot, Iain Darby, Mark Huyse, Takaharu Otsuka, R. R. Rodríguez-Guzmán, Liam Gaffney, R. Gernhäuser, P. Van Duppen, R. Krücken, Fredrik Wenander, Vinzenz Bildstein, N. Warr, M. Zielinska, D. Mücher, T. Kröll, B. S. Nara Singh, C. Mihai, M. Seidlitz, Joakim Cederkäll, Georgi P. Georgiev, B. Bastin, P. Thöle, D. Radeck, Susan Rigby, S. Das Gupta, D. G. Jenkins, M. Albers, C. Fransen, J. Van de Walle, R. Wadsworth, Pedro Sarriguren, T. Thomas, B. Siebeck, J. Jolie, Marcus Scheck, N. Marginean, M. Hackstein, D. M. Filipescu, L. Bettermann, Janne Pakarinen, Thomas Davinson, G. S. Simpson, P. J. Napiorkowski, E. Fiori, A. Blazhev, K. Nowak, L. M. Robledo, Joonas Konki, M. Kowalczyk, R. Lutter, Herbert Hess, K. O. Zell, Kathrin Wimmer, Kosuke Nomura, M. Vermeulen, M. Cappellazzo, Stefan Heinze, J. Litzinger, D. Cline, C. Bauer, CSNSM SNO, Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse (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)-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)-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), Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS), REX-ISOLDE, Research unit Nuclear & Hadron Physics, and UAM. Departamento de Física Teórica

Subjects
Quantum phase transition, [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], REX-ISOLDE, Nuclear Theory, QUANTUM PHASE-TRANSITIONS, General Physics and Astronomy, chemistry.chemical_element, Context (language use), Coulomb excitation, Nuclear Structure, 01 natural sciences, REGION, Nuclear physics, 0103 physical sciences, Nuclear Physics - Experiment, Neutron, 010306 general physics, Nuclear Experiment, DETECTOR, INTERACTING BOSONS, Physics, EXCITATIONS, COLLECTIVE NUCLEAR-STATES, ta114, 010308 nuclear & particles physics, Krypton, Física, chemistry, Excited state, SHELL-MODEL, Interacting boson model, Atomic physics, Ground state
Abstract

The neutron-rich nuclei Kr94,96 were studied via projectile Coulomb excitation at the REX-ISOLDE facility at CERN. Level energies of the first excited 2 + states and their absolute E2 transition strengths to the ground state are determined and discussed in the context of the E(21+) and B(E2;21+→01+) systematics of the krypton chain. Contrary to previously published results no sudden onset of deformation is observed. This experimental result is supported by a new proton-neutron interacting boson model calculation based on the constrained Hartree-Fock-Bogoliubov approach using the microscopic Gogny-D1M energy density functional. © 2012 American Physical Society., This work was supported by the BMBF under Contracts No. 06KY9136 and No. 06MT238, by ENSAR, by the DFG Cluster of Excellence Origin and Structure of the Universe, and by the grant-in-aid for scientific research for JSPS Fellows (Grant No. 217368). One of the authors (J. D.) would like to acknowledge the support of FWOVlaanderen (Belgium).

Published
2012
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82. In-beam fast-timing measurements inCd103,105,107

Author

I. Căta-Danil, P. Detistov, K. O. Zell, D. L. Balabanski, S. Lalkovski, N. Marginean, D. Bucurescu, D. S. Judson, T. Glodariu, M. Rudigier, A. Negret, D. Deleanu, L. Stroe, L. Atanasova, N. V. Zamfir, T. Sava, D. M. Filipescu, D. Ghiţă, Georgi P. Georgiev, Gh. Căta-Danil, S. Pascu, R. Lozeva, J. Jolie, J.-M. Régis, S. Kisyov, R. Mărginean, G. Suliman, C. Mihai, D. Radulov, M. Zhekova, and J. M. Daugas

Subjects
Physics, Nuclear and High Energy Physics, Fusion, Isotope, 010308 nuclear & particles physics, Evaporation, Half-life, 7. Clean energy, 01 natural sciences, Nuclear physics, Isotopes of cadmium, 0103 physical sciences, Atomic physics, 010306 general physics, Radioactive decay, Excitation, Beam (structure)
Abstract

Fast-timing measurements were performed in the region of the medium-mass $^{103,105,107}\mathrm{Cd}$ isotopes, produced in fusion evaporation reactions. Results on new and reevaluated half-lives are analyzed within a systematic study of transition rates. The $7/{2}_{1}^{+}$ states in $^{103,105,107}\mathrm{Cd}$ are interpreted as arising from a single-particle excitation. The $9/{2}^{+}$ states configuration assignment is based on the observed decay branches.

Published
2011
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83. The Generalized Centroid Difference method for lifetime measurements viaγ-γcoincidences using large fast-timing arrays

Author

F. Drouet, Zs. Podolyák, Aurelien Blanc, Alison Bruce, O. Stezowski, Gheorghe Pascovici, T. Kröll, W. Korten, T. Soldner, J.-M. Régis, S. Mărginean, Henryk Mach, N. Warr, Ulli Köster, J. Jolie, P.H. Regan, M. Rudigier, Paolo Mutti, G.S. Simpson, W. Urban, Michael Jentschel, V. Paziy, S. Lalkovski, M. Pfeiffer, C. A. Ur, A. Vancraeyenest, S. Ilieva, L. M. Fraile, N. Saed-Samii, A. Blazhev, Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Institut Laue-Langevin (ILL), ILL, 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), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), 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), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-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)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, business.industry, QC1-999, Detector, Centroid, Observable, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Scintillator, Spectral line, Computational physics, Superposition principle, Optics, Cascade, Excited state, business
Abstract

This is an Open Access article distributed under the terms of the Creative Common Attribution Licence 4.0 which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.; International audience; A novel method for direct electronic "fast-timing" lifetime measurements of nuclear excited statesvia γ-γ coincidences using an array equipped with N very fast high-resolution LaBr3(Ce) scintillator detectorsis presented. The generalized centroid difference method provides two independent “start” and “stop” timespectra obtained without any correction by a superposition of the N(N − 1)/2 calibrated γ-γ time differencespectra of the N detector fast-timing system. The two fast-timing array time spectra correspond to a forwardand reverse gating of a specific γ-γ cascade and the centroid difference as the time shift between the centroidsof the two time spectra provides a picosecond-sensitive mirror-symmetric observable of the set-up. The energydependentmean prompt response difference between the start and stop events is calibrated and used as a singlecorrection for lifetime determination. These combined fast-timing array mean γ-γ zero-time responses can bedetermined for 40 keV < Eγ < 1.4 MeV with a precision better than 10 ps using a 152Eu γ-ray source. Thenew method is described with examples of (n,γ) and (n,f,γ) experiments performed at the intense cold-neutronbeam facility PF1B of the Institut Laue-Langevin in Grenoble, France, using 16 LaBr3(Ce) detectors withinthe EXILL&FATIMA campaign in 2013. The results are discussed with respect to possible systematic errorsinduced by background contributions.

Published
2015
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84. Mesenterico-caval shunt in rats

Author

J. F. M. Rudigier, J. Grönniger, and P. Wendling

Subjects
Male, medicine.medical_specialty, medicine.diagnostic_test, business.industry, Angiography, Vena Cava, Inferior, General Medicine, Microsurgical procedure, Mesenteric Vein, Rats, Shunt (medical), Surgery, body regions, Shunting, Portal System, Mesenteric Veins, surgical procedures, operative, Portal blood, Methods, cardiovascular system, Animals, Medicine, Blood supply, business
Abstract

A microsurgical technique for mesenterico-caval shunting in the rat is described. The method results in a partial blood drainage from the upper abdominal content whereas the blood of the mesenteric vein is shunted to the inferior caval vein. Controls were undertaken after 1 and 3 weeks, either visually or radiologically. Twenty-two of 26 surviving animals showed patency of the shunt. All animals had undisturbed blood supply to the portal stump.

Published
1980
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85. Pathogenesis of circulatory reactions triggered by nervous reflexes during the implantation of bone cements

Author

G. Ritter and J. F. M. Rudigier

Subjects
Nervous system, Male, Pathology, medicine.medical_specialty, Medullary cavity, medicine.medical_treatment, Blood Pressure, Vagotomy, Bone Marrow, Heart Rate, Reflex, medicine, Animals, Lung, Tibia, business.industry, Respiration, Bone Cements, General Medicine, Ganglion, Atropine, medicine.anatomical_structure, Circulatory system, Female, Bone marrow, Rabbits, business, medicine.drug
Abstract

Circulatory and respiratory reactions during the implantation of joint endoprostheses have been observed for years. The components of the bone cements used for anchoring (methyl methacrylate monomer) or the outpour of bone marrow substances from the affected bone marrow cavity are thought to be chiefly responsible for these effects. However, our previous investigations demonstrated unambiguously that reactions of this type can be attributed to direct nervous-reflex mechanisms triggered by the pressure rise in the medullary canal, and that, in addition, bone marrow embolism plays a part in serious circulatory incidents. The investigations on which the present paper is based have confirmed the mechanism of circulatory reactions triggered by direct nervous reflex and have shown once again that the release of cement monomers is not of any significance, at least not in animal experiments. In regard of the characteristics of these reflex processes, it has been possible to show by both surgical and pharmacologic interventions in the vegetative nervous system, performed before and during pressure experiments, that these reflex processes are caused not so much by an increase of the vagus tone as by a central inhibition of the sympathicus. Neither administrations of atropine nor bilateral cervical vagotomy are able to prevent the reactions. This was only possible under the influence of a ganglion blocker.

Published
1983

88. Angular momentum generation in nuclear fission.

Author

Wilson JN, Thisse D, Lebois M, Jovančević N, Gjestvang D, Canavan R, Rudigier M, Étasse D, Gerst RB, Gaudefroy L, Adamska E, Adsley P, Algora A, Babo M, Belvedere K, Benito J, Benzoni G, Blazhev A, Boso A, Bottoni S, Bunce M, Chakma R, Cieplicka-Oryńczak N, Courtin S, Cortés ML, Davies P, Delafosse C, Fallot M, Fornal B, Fraile L, Gottardo A, Guadilla V, Häfner G, Hauschild K, Heine M, Henrich C, Homm I, Ibrahim F, Iskra ŁW, Ivanov P, Jazrawi S, Korgul A, Koseoglou P, Kröll T, Kurtukian-Nieto T, Le Meur L, Leoni S, Ljungvall J, Lopez-Martens A, Lozeva R, Matea I, Miernik K, Nemer J, Oberstedt S, Paulsen W, Piersa M, Popovitch Y, Porzio C, Qi L, Ralet D, Regan PH, Rezynkina K, Sánchez-Tembleque V, Siem S, Schmitt C, Söderström PA, Sürder C, Tocabens G, Vedia V, Verney D, Warr N, Wasilewska B, Wiederhold J, Yavahchova M, Zeiser F, and Ziliani S

Abstract

When a heavy atomic nucleus splits (fission), the resulting fragments are observed to emerge spinning 1 ; this phenomenon has been a mystery in nuclear physics for over 40 years 2,3 . The internal generation of typically six or seven units of angular momentum in each fragment is particularly puzzling for systems that start with zero, or almost zero, spin. There are currently no experimental observations that enable decisive discrimination between the many competing theories for the mechanism that generates the angular momentum 4-12 . Nevertheless, the consensus is that excitation of collective vibrational modes generates the intrinsic spin before the nucleus splits (pre-scission). Here we show that there is no significant correlation between the spins of the fragment partners, which leads us to conclude that angular momentum in fission is actually generated after the nucleus splits (post-scission). We present comprehensive data showing that the average spin is strongly mass-dependent, varying in saw-tooth distributions. We observe no notable dependence of fragment spin on the mass or charge of the partner nucleus, confirming the uncorrelated post-scission nature of the spin mechanism. To explain these observations, we propose that the collective motion of nucleons in the ruptured neck of the fissioning system generates two independent torques, analogous to the snapping of an elastic band. A parameterization based on occupation of angular momentum states according to statistical theory describes the full range of experimental data well. This insight into the role of spin in nuclear fission is not only important for the fundamental understanding and theoretical description of fission, but also has consequences for the γ-ray heating problem in nuclear reactors 13,14 , for the study of the structure of neutron-rich isotopes 15,16 , and for the synthesis and stability of super-heavy elements 17,18 .

Published
2021
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89. Competition between Allowed and First-Forbidden β Decay: The Case of ^{208}Hg→^{208}Tl.

Author

Carroll RJ, Podolyák Z, Berry T, Grawe H, Alexander T, Andreyev AN, Ansari S, Borge MJG, Brunet M, Creswell JR, Fraile LM, Fahlander C, Fynbo HOU, Gamba ER, Gelletly W, Gerst RB, Górska M, Gredley A, Greenlees PT, Harkness-Brennan LJ, Huyse M, Judge SM, Judson DS, Konki J, Kurcewicz J, Kuti I, Lalkovski S, Lazarus IH, Lică R, Lund M, Madurga M, Marginean N, Marginean R, Marroquin I, Mihai C, Mihai RE, Nácher E, Negret A, Nita C, Pascu S, Page RD, Patel Z, Perea A, Phrompao J, Piersa M, Pucknell V, Rahkila P, Rapisarda E, Regan PH, Rotaru F, Rudigier M, Shand CM, Shearman R, Stegemann S, Stora T, Sotty C, Tengblad O, Van Duppen P, Vedia V, Wadsworth R, Walker PM, Warr N, Wearing F, and De Witte H

Abstract

The β decay of ^{208}Hg into the one-proton hole, one neutron-particle &#95;{81}^{208}Tl&#95;{127} nucleus was investigated at CERN-ISOLDE. Shell-model calculations describe well the level scheme deduced, validating the proton-neutron interactions used, with implications for the whole of the N>126, Z<82 quadrant of neutron-rich nuclei. While both negative and positive parity states with spin 0 and 1 are expected within the Q&#95;{β} window, only three negative parity states are populated directly in the β decay. The data provide a unique test of the competition between allowed Gamow-Teller and Fermi, and first-forbidden β decays, essential for the understanding of the nucleosynthesis of heavy nuclei in the rapid neutron capture process. Furthermore, the observation of the parity changing 0^{+}→0^{-}β decay where the daughter state is core excited is unique, and can provide information on mesonic corrections of effective operators.

Published
2020
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90. Sequential Nature of (p,3p) Two-Proton Knockout from Neutron-Rich Nuclei.

Author

Frotscher A, Gómez-Ramos M, Obertelli A, Doornenbal P, Authelet G, Baba H, Calvet D, Château F, Chen S, Corsi A, Delbart A, Gheller JM, Giganon A, Gillibert A, Isobe T, Lapoux V, Matsushita M, Momiyama S, Motobayashi T, Niikura M, Otsu H, Paul N, Péron C, Peyaud A, Pollacco EC, Roussé JY, Sakurai H, Santamaria C, Sasano M, Shiga Y, Shimizu N, Steppenbeck D, Takeuchi S, Taniuchi R, Uesaka T, Wang H, Yoneda K, Ando T, Arici T, Blazhev A, Browne F, Bruce AM, Carroll R, Chung LX, Cortés ML, Dewald M, Ding B, Dombradi Z, Flavigny F, Franchoo S, Giacoppo F, Górska M, Gottardo A, Hadyńska-Klęk K, Korkulu Z, Koyama S, Kubota Y, Jungclaus A, Lee J, Lettmann M, Linh BD, Liu J, Liu Z, Lizarazo C, Louchart C, Lozeva R, Matsui K, Miyazaki T, Moschner K, Nagamine S, Nakatsuka N, Nita C, Nishimura S, Nobs CR, Olivier L, Ota S, Patel Z, Podolyák Z, Rudigier M, Sahin E, Saito TY, Shand C, Söderström PA, Stefan IG, Sumikama T, Suzuki D, Orlandi R, Vaquero V, Vajta Z, Werner V, Wimmer K, Wu J, and Xu Z

Abstract

Twenty-one two-proton knockout (p,3p) cross sections were measured from neutron-rich nuclei at ∼250  MeV/nucleon in inverse kinematics. The angular distribution of the three emitted protons was determined for the first time, demonstrating that the (p,3p) kinematics are consistent with two sequential proton-proton collisions within the projectile nucleus. Ratios of (p,3p) over (p,2p) inclusive cross sections follow the trend of other many-nucleon removal reactions, further reinforcing the sequential nature of (p,3p) in neutron-rich nuclei.

Published
2020
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91. Metastable States of ^{92,94}Se: Identification of an Oblate K Isomer of ^{94}Se and the Ground-State Shape Transition between N=58 and 60.

Author

Lizarazo C, Söderström PA, Werner V, Pietralla N, Walker PM, Dong GX, Xu FR, Rodríguez TR, Browne F, Doornenbal P, Nishimura S, Niţă CR, Obertelli A, Ando T, Arici T, Authelet G, Baba H, Blazhev A, Bruce AM, Calvet D, Caroll RJ, Château F, Chen S, Chung LX, Corsi A, Cortés ML, Delbart A, Dewald M, Ding B, Flavigny F, Franchoo S, Gerl J, Gheller JM, Giganon A, Gillibert A, Górska M, Gottardo A, Kojouharov I, Kurz N, Lapoux V, Lee J, Lettmann M, Linh BD, Liu JJ, Liu Z, Momiyama S, Moschner K, Motobayashi T, Nagamine S, Nakatsuka N, Niikura M, Nobs C, Olivier L, Patel Z, Paul N, Podolyák Z, Roussé JY, Rudigier M, Saito TY, Sakurai H, Santamaria C, Schaffner H, Shand C, Stefan I, Steppenbeck D, Taniuchi R, Uesaka T, Vaquero V, Wimmer K, and Xu Z

Abstract

Here we present new information on the shape evolution of the very neutron-rich ^{92,94}Se nuclei from an isomer-decay spectroscopy experiment at the Radioactive Isotope Beam Factory at RIKEN. High-resolution germanium detectors were used to identify delayed γ rays emitted following the decay of their isomers. New transitions are reported extending the previously known level schemes. The isomeric levels are interpreted as originating from high-K quasineutron states with an oblate deformation of β∼0.25, with the high-K state in ^{94}Se being metastable and K hindered. Following this, ^{94}Se is the lowest-mass neutron-rich nucleus known to date with such a substantial K hindrance. Furthermore, it is the first observation of an oblate K isomer in a deformed nucleus. This opens up the possibility for a new region of K isomers at low Z and at oblate deformation, involving the same neutron orbitals as the prolate orbitals within the classic Z∼72 deformed hafnium region. From an interpretation of the level scheme guided by theoretical calculations, an oblate deformation is also suggested for the ^{94}Se&#95;{60} ground-state band.

Published
2020
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92. Advances in the Direct Study of Carbon Burning in Massive Stars.

Author

Fruet G, Courtin S, Heine M, Jenkins DG, Adsley P, Brown A, Canavan R, Catford WN, Charon E, Curien D, Della Negra S, Duprat J, Hammache F, Lesrel J, Lotay G, Meyer A, Montanari D, Morris L, Moukaddam M, Nippert J, Podolyák Z, Regan PH, Ribaud I, Richer M, Rudigier M, Shearman R, de Séréville N, and Stodel C

Abstract

The ^{12}C+^{12}C fusion reaction plays a critical role in the evolution of massive stars and also strongly impacts various explosive astrophysical scenarios. The presence of resonances in this reaction at energies around and below the Coulomb barrier makes it impossible to carry out a simple extrapolation down to the Gamow window-the energy regime relevant to carbon burning in massive stars. The ^{12}C+^{12}C system forms a unique laboratory for challenging the contemporary picture of deep sub-barrier fusion (possible sub-barrier hindrance) and its interplay with nuclear structure (sub-barrier resonances). Here, we show that direct measurements of the ^{12}C+^{12}C fusion cross section may be made into the Gamow window using an advanced particle-gamma coincidence technique. The sensitivity of this technique effectively removes ambiguities in existing measurements made with gamma ray or charged-particle detection alone. The present cross-section data span over 8 orders of magnitude and support the fusion-hindrance model at deep sub-barrier energies.

Published
2020
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93. Prominence of Pairing in Inclusive (p,2p) and (p,pn) Cross Sections from Neutron-Rich Nuclei.

Author

Paul N, Obertelli A, Bertulani CA, Corsi A, Doornenbal P, Rodriguez-Sanchez JL, Authelet G, Baba H, Calvet D, Château F, Chen S, Delbart A, Gheller JM, Giganon A, Gillibert A, Isobe T, Lapoux V, Matsushita M, Momiyama S, Motobayashi T, Niikura M, Otsu H, Péron C, Peyaud A, Pollacco EC, Roussé JY, Sakurai H, Santamaria C, Sasano M, Shiga Y, Steppenbeck D, Takeuchi S, Taniuchi R, Uesaka T, Wang H, Yoneda K, Ando T, Arici T, Blazhev A, Browne F, Bruce AM, Carroll R, Chung LX, Cortés ML, Dewald M, Ding B, Dombradi Z, Flavigny F, Franchoo S, Giacoppo F, Górska M, Gottardo A, Hadynska-Klek K, Korkulu Z, Koyama S, Kubota Y, Jungclaus A, Lee J, Lettmann M, Linh BD, Liu J, Liu Z, Lizarazo C, Louchart C, Lozeva R, Matsui K, Miyazaki T, Moschner K, Nagamine S, Nakatsuka N, Nita C, Nishimura S, Nobs CR, Olivier L, Ota S, Patel Z, Podolyák Z, Rudigier M, Sahin E, Saito TY, Shand C, Söderström PA, Stefan IG, Sumikama T, Suzuki D, Orlandi R, Vaquero V, Vajta Z, Werner V, Wimmer K, Wu J, and Xu Z

Abstract

Fifty-five inclusive single nucleon-removal cross sections from medium mass neutron-rich nuclei impinging on a hydrogen target at ∼250  MeV/nucleon are measured at the RIKEN Radioactive Isotope Beam Factory. Systematically higher cross sections are found for proton removal from nuclei with an even number of protons as compared to odd-proton number projectiles for a given neutron separation energy. Neutron removal cross sections display no even-odd splitting, contrary to nuclear cascade model predictions. Both effects are understood through simple considerations of neutron separation energies and bound state level densities originating in pairing correlations in the daughter nuclei. These conclusions are supported by comparison with semimicroscopic model predictions, highlighting the enhanced role of low-lying level densities in nucleon-removal cross sections from loosely bound nuclei.

Published
2019
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94. Shape Evolution in Neutron-Rich Krypton Isotopes Beyond N=60: First Spectroscopy of ^{98,100}Kr.

Author

Flavigny F, Doornenbal P, Obertelli A, Delaroche JP, Girod M, Libert J, Rodriguez TR, Authelet G, Baba H, Calvet D, Château F, Chen S, Corsi A, Delbart A, Gheller JM, Giganon A, Gillibert A, Lapoux V, Motobayashi T, Niikura M, Paul N, Roussé JY, Sakurai H, Santamaria C, Steppenbeck D, Taniuchi R, Uesaka T, Ando T, Arici T, Blazhev A, Browne F, Bruce A, Carroll R, Chung LX, Cortés ML, Dewald M, Ding B, Franchoo S, Górska M, Gottardo A, Jungclaus A, Lee J, Lettmann M, Linh BD, Liu J, Liu Z, Lizarazo C, Momiyama S, Moschner K, Nagamine S, Nakatsuka N, Nita C, Nobs CR, Olivier L, Orlandi R, Patel Z, Podolyák Z, Rudigier M, Saito T, Shand C, Söderström PA, Stefan I, Vaquero V, Werner V, Wimmer K, and Xu Z

Abstract

We report on the first γ-ray spectroscopy of low-lying states in neutron-rich ^{98,100}Kr isotopes obtained from ^{99,101}Rb(p,2p) reactions at ∼220  MeV/nucleon. A reduction of the 2&#95;{1}^{+} state energies beyond N=60 demonstrates a significant increase of deformation, shifted in neutron number compared to the sharper transition observed in strontium and zirconium isotopes. State-of-the-art beyond-mean-field calculations using the Gogny D1S interaction predict level energies in good agreement with experimental results. The identification of a low-lying (0&#95;{2}^{+}, 2&#95;{2}^{+}) state in ^{98}Kr provides the first experimental evidence of a competing configuration at low energy in neutron-rich krypton isotopes consistent with the oblate-prolate shape coexistence picture suggested by theory.

Published
2017
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95. Are There Signatures of Harmonic Oscillator Shells Far from Stability? First Spectroscopy of ^{110}Zr.

Author

Paul N, Corsi A, Obertelli A, Doornenbal P, Authelet G, Baba H, Bally B, Bender M, Calvet D, Château F, Chen S, Delaroche JP, Delbart A, Gheller JM, Giganon A, Gillibert A, Girod M, Heenen PH, Lapoux V, Libert J, Motobayashi T, Niikura M, Otsuka T, Rodríguez TR, Roussé JY, Sakurai H, Santamaria C, Shimizu N, Steppenbeck D, Taniuchi R, Togashi T, Tsunoda Y, Uesaka T, Ando T, Arici T, Blazhev A, Browne F, Bruce AM, Carroll R, Chung LX, Cortés ML, Dewald M, Ding B, Flavigny F, Franchoo S, Górska M, Gottardo A, Jungclaus A, Lee J, Lettmann M, Linh BD, Liu J, Liu Z, Lizarazo C, Momiyama S, Moschner K, Nagamine S, Nakatsuka N, Nita C, Nobs CR, Olivier L, Patel Z, Podolyák Z, Rudigier M, Saito T, Shand C, Söderström PA, Stefan I, Orlandi R, Vaquero V, Werner V, Wimmer K, and Xu Z

Abstract

The first measurement of the low-lying states of the neutron-rich ^{110}Zr and ^{112}Mo was performed via in-beam γ-ray spectroscopy after one proton removal on hydrogen at ∼200  MeV/nucleon. The 2&#95;{1}^{+} excitation energies were found at 185(11) keV in ^{110}Zr, and 235(7) keV in ^{112}Mo, while the R&#95;{42}=E(4&#95;{1}^{+})/E(2&#95;{1}^{+}) ratios are 3.1(2), close to the rigid rotor value, and 2.7(1), respectively. These results are compared to modern energy density functional based configuration mixing models using Gogny and Skyrme effective interactions. We conclude that first levels of ^{110}Zr exhibit a rotational behavior, in agreement with previous observations of lighter zirconium isotopes as well as with the most advanced Monte Carlo shell model predictions. The data, therefore, do not support a harmonic oscillator shell stabilization scenario at Z=40 and N=70. The present data also invalidate predictions for a tetrahedral ground state symmetry in ^{110}Zr.

Published
2017
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96. Studies of pear-shaped nuclei using accelerated radioactive beams.

Author

Gaffney LP, Butler PA, Scheck M, Hayes AB, Wenander F, Albers M, Bastin B, Bauer C, Blazhev A, Bönig S, Bree N, Cederkäll J, Chupp T, Cline D, Cocolios TE, Davinson T, De Witte H, Diriken J, Grahn T, Herzan A, Huyse M, Jenkins DG, Joss DT, Kesteloot N, Konki J, Kowalczyk M, Kröll T, Kwan E, Lutter R, Moschner K, Napiorkowski P, Pakarinen J, Pfeiffer M, Radeck D, Reiter P, Reynders K, Rigby SV, Robledo LM, Rudigier M, Sambi S, Seidlitz M, Siebeck B, Stora T, Thoele P, Van Duppen P, Vermeulen MJ, von Schmid M, Voulot D, Warr N, Wimmer K, Wrzosek-Lipska K, Wu CY, and Zielinska M

Abstract

There is strong circumstantial evidence that certain heavy, unstable atomic nuclei are 'octupole deformed', that is, distorted into a pear shape. This contrasts with the more prevalent rugby-ball shape of nuclei with reflection-symmetric, quadrupole deformations. The elusive octupole deformed nuclei are of importance for nuclear structure theory, and also in searches for physics beyond the standard model; any measurable electric-dipole moment (a signature of the latter) is expected to be amplified in such nuclei. Here we determine electric octupole transition strengths (a direct measure of octupole correlations) for short-lived isotopes of radon and radium. Coulomb excitation experiments were performed using accelerated beams of heavy, radioactive ions. Our data on (220)Rn and (224)Ra show clear evidence for stronger octupole deformation in the latter. The results enable discrimination between differing theoretical approaches to octupole correlations, and help to constrain suitable candidates for experimental studies of atomic electric-dipole moments that might reveal extensions to the standard model.

Published
2013
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97. Characterisation of diamond coatings with different morphologies by Raman spectroscopy using various laser wavelengths.

Author

Rudigier M and Haubner R

Abstract

Since the beginning of low-pressure diamond synthesis, Raman spectroscopy has been widely used to identify and characterise the quality of diamonds. The diamond crystal is characterised by a Raman peak at about 1,332 cm(-1). Other peaks are associated with miscellaneous carbon structures, e.g. graphite and amorphous phases. In recent years, both well-faceted crystalline diamonds and nanocrystalline and ultrananocrystalline diamonds have been investigated. For these fine-grained materials, the diamond peak at 1,332 cm(-1) disappears and the intensities of peaks at other wavelengths increase. To study the influence of the Raman laser wavelength, three lasers were used (472.681 nm, blue; 532.1 nm, green; 632.81 nm, red). For well-faceted diamonds, the Raman spectra with blue and green laser light were similar. A shift of the peak maxima and different intensities were observed. With use of the red laser, a strong luminescence peak and low peak intensities for the various carbon-related peaks occurred. When the diamond morphology changes from well-faceted to fine-grained ballas diamond, the spectra are similar for all three lasers.

Published
2012
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98. Evidence for a smooth onset of deformation in the neutron-rich Kr isotopes.

Author

Albers M, Warr N, Nomura K, Blazhev A, Jolie J, Mücher D, Bastin B, Bauer C, Bernards C, Bettermann L, Bildstein V, Butterworth J, Cappellazzo M, Cederkäll J, Cline D, Darby I, Das Gupta S, Daugas JM, Davinson T, De Witte H, Diriken J, Filipescu D, Fiori E, Fransen C, Gaffney LP, Georgiev G, Gernhäuser R, Hackstein M, Heinze S, Hess H, Huyse M, Jenkins D, Konki J, Kowalczyk M, Kröll T, Krücken R, Litzinger J, Lutter R, Marginean N, Mihai C, Moschner K, Napiorkowski P, Singh BS, Nowak K, Otsuka T, Pakarinen J, Pfeiffer M, Radeck D, Reiter P, Rigby S, Robledo LM, Rodríguez-Guzmán R, Rudigier M, Sarriguren P, Scheck M, Seidlitz M, Siebeck B, Simpson G, Thöle P, Thomas T, Van de Walle J, Van Duppen P, Vermeulen M, Voulot D, Wadsworth R, Wenander F, Wimmer K, Zell KO, and Zielinska M

Abstract

The neutron-rich nuclei 94,96Kr were studied via projectile Coulomb excitation at the REX-ISOLDE facility at CERN. Level energies of the first excited 2(+) states and their absolute E2 transition strengths to the ground state are determined and discussed in the context of the E(2(1)(+)) and B(E2;2(1)(+)→0(1)(+)) systematics of the krypton chain. Contrary to previously published results no sudden onset of deformation is observed. This experimental result is supported by a new proton-neutron interacting boson model calculation based on the constrained Hartree-Fock-Bogoliubov approach using the microscopic Gogny-D1M energy density functional.

Published
2012
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