The Experts below are selected from a list of 198 Experts worldwide ranked by ideXlab platform
R. W. Hoff - One of the best experts on this subject based on the ideXlab platform.
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Nuclear structure in Odd-Odd Nuclei, 144
Reviews of Modern Physics, 1998Co-Authors: Ashok Kumar Jain, Raymond K. Sheline, D.m. Headly, P. C. Sood, D. G. Burke, I. Hrĭvnácová, J. Kvasil, D. Nosek, R. W. HoffAbstract:A comprehensive review of the present understanding, both theoretical and experimental, of intrinsic and rotational level structures in medium-heavy deformed Odd-Odd Nuclei is presented. A discussion of the various experimental methods is presented, emphasizing the need for a variety of experimental approaches. The Odd-Odd Nuclei that are immediately amenable to fruitful additional study are pointed out. A discussion of the intrinsic level structures, Gallagher-Moszkowski (GM) splittings, Newby (N) shifts, and role of the residual p-n interaction is presented. Currently available data in the rare-earth region allow the empirical determination of 137 GM splittings and 36 N shifts for 25 Odd-Odd Nuclei in the mass region 152{le}A{le}188. A new parametrization of the residual p-n interaction is presented which also takes into account the 27 GM splittings and 12 N shifts from the actinide region. Newly discovered features of rotational bands, such as odd-even staggering, and other high-spin phenomena, such as signature inversion and delay in bandcrossing frequency, are discussed. The role of higher-order Coriolis coupling is pointed out. Systematics of the two-quasiparticle excitations, shape coexistence, isomers, and four-quasiparticle states are presented. Calculated results of the two-quasiparticle intrinsic excitations using two methods, the intrinsic level spacings for odd-{ital A} neighboring Nuclei andmore » the quasiparticle-plus-phonon coupling model, are compared with experiment. {copyright} {ital 1998} {ital The American Physical Society}« less
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Survey of experimental data: The n-p interaction in deformed Odd-Odd Nuclei
Bulletin of the American Physical Society, 1993Co-Authors: R. W. HoffAbstract:Experimental data and configuration assignments for quasiparticle excitations in deformed Odd-Odd Nuclei in the rare earth region have been critically surveyed. A set of most reliable values for Gallagher-Moszkowski matrix elements has been derived for comparison with calculations. Of particular interest are the sensitivities of the calculated results to variables such as nuclear shape and the parameters that describe the nucleon-nucleon force. After many years of study, the n-p interaction, as manifested in the nuclear structure of Odd-Odd Nuclei, still has not been characterized satisfactorily. Progress to date in understanding these phenomena will be summarized.
J.a. Pinston - One of the best experts on this subject based on the ideXlab platform.
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Shape coexistence in odd and Odd-Odd Nuclei in the A = 100 region
BgNS Transactions, 2005Co-Authors: J.a. PinstonAbstract:The region of neutron rich Nuclei near A=100 is distinctive for the sudden change in the ground state properties of Nuclei. In particular, for the even $_{38}$Sr and $_{40}$Zr isotopes a sudden onset of strong deformations at N=60 is observed, whereas the lighter isotopes up to N=58 are rather spherical. The isotones with N=59 neutrons are of special interest because they are just at the border between the two regions. Very recently, we have studied these odd-neutrons and Odd-Odd Nuclei, by means of prompt-gamma spectroscopy of spontaneous fission of $^248}$Cm, using EUROGAM2 multidetector, and by measurements of microsecond isomers produced by fission of $^{241}$Pu at ILL reactor (Grenoble). In the latter case, the detection is based on time correlations between fission fragments selected by the LOHENGRIN mass spectrometer, and gamma-rays and conversion electrons from the isomers. It was found that in the odd Nuclei of Sr and Zr three different shapes coexist. The ground state and low-lying levels are rather spherical, while deformed bands with $\beta_2$=0.3 are present at about 600 keV and the maximum deformation of the mass region, $\beta_2$=0.42 is reached for bands at about 1 MeV excitation energy. In the Odd-Odd Nuclei, only two different shapes were found: the low-lying levels are rather spherical and deformed bands appear at about 500 keV. These new data allow to understand the origin of the deformation and the shape coexistence phenomenon observed in this mass region. The predominant role played by the unique-parity state $\nu g_{9/2}$ and $\nu h_{11/2}$ will be discussed.
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Shape coexistence in odd and Odd-Odd Nuclei in the A $\sim$ 100 region
2005Co-Authors: J.a. Pinston, J. Genevey, G.s. Simpson, W. UrbanAbstract:In the even-even Nuclei around A=100 a transition from spherical to deformed shapes occurs from N=58 to N=60. The isotones with N=59 are of special interest, because they are just at the border between the two regions. Very recently, we have studied odd-neutrons and Odd-Odd Nuclei with N=59, by means of prompt $\gamma$-ray spectroscopy of the spontaneous fission of $^{247}$Cm, using the EUROGAM 2 multi-detector, and by measurements of $\mu$s isomers produced by fission of $^{239,241}$Pu with thermal neutrons at ILL (Grenoble). In the latter case, the detection is based on time correlation measurements between fission fragments detected by the LOHENGRIN mass spectrometer and $\gamma$-rays or conversion electrons from the isomer decay. It was found that three shapes coexist in the odd $^{97}$Sr and $^{99}$Zr and two shapes coexist in the Odd-Odd $^{96}$Rb. A simple explanation of the shape-coexistence mechanism is proposed. It is based upon the Nilsson diagram and stresses the fundamental importance of the unique parity states.
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Shape Coexistence In Odd And Odd‐Odd Nuclei In The A∼100 Region
AIP Conference Proceedings, 2005Co-Authors: J.a. Pinston, J. Genevey, G. Simpson, W. UrbanAbstract:In the even‐even Nuclei around A=100 a transition from spherical to deformed shapes occurs from N =58 to N=60. The isotones with N=59 are of special interest, because they are just at the border between the two regions. Very recently, we have studied odd‐neutrons and odd‐odd Nuclei with N=59, by means of prompt γ‐ray spectroscopy of the spontaneous fission of 248Cm, using the EUROGAM 2 multi‐detector, and by measurements of μs isomers produced by fission of 239,241Pu with thermal neutrons at ILL (Grenoble). In the latter case, the detection is based on time correlation measurements between fission fragments detected by the LOHENGRIN mass spectrometer and γ‐rays or conversion electrons from the isomer decay. It was found that three shapes coexist in the odd 97Sr and 99Zr and two shapes coexist in the odd‐odd 96Rb. A simple explanation of the shape‐coexistence mechanism is proposed. It is based upon the Nilsson diagram and stresses the fundamental importance of the unique parity states.
W. Urban - One of the best experts on this subject based on the ideXlab platform.
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Shape coexistence in odd and Odd-Odd Nuclei in the A $\sim$ 100 region
2005Co-Authors: J.a. Pinston, J. Genevey, G.s. Simpson, W. UrbanAbstract:In the even-even Nuclei around A=100 a transition from spherical to deformed shapes occurs from N=58 to N=60. The isotones with N=59 are of special interest, because they are just at the border between the two regions. Very recently, we have studied odd-neutrons and Odd-Odd Nuclei with N=59, by means of prompt $\gamma$-ray spectroscopy of the spontaneous fission of $^{247}$Cm, using the EUROGAM 2 multi-detector, and by measurements of $\mu$s isomers produced by fission of $^{239,241}$Pu with thermal neutrons at ILL (Grenoble). In the latter case, the detection is based on time correlation measurements between fission fragments detected by the LOHENGRIN mass spectrometer and $\gamma$-rays or conversion electrons from the isomer decay. It was found that three shapes coexist in the odd $^{97}$Sr and $^{99}$Zr and two shapes coexist in the Odd-Odd $^{96}$Rb. A simple explanation of the shape-coexistence mechanism is proposed. It is based upon the Nilsson diagram and stresses the fundamental importance of the unique parity states.
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Shape Coexistence In Odd And Odd‐Odd Nuclei In The A∼100 Region
AIP Conference Proceedings, 2005Co-Authors: J.a. Pinston, J. Genevey, G. Simpson, W. UrbanAbstract:In the even‐even Nuclei around A=100 a transition from spherical to deformed shapes occurs from N =58 to N=60. The isotones with N=59 are of special interest, because they are just at the border between the two regions. Very recently, we have studied odd‐neutrons and odd‐odd Nuclei with N=59, by means of prompt γ‐ray spectroscopy of the spontaneous fission of 248Cm, using the EUROGAM 2 multi‐detector, and by measurements of μs isomers produced by fission of 239,241Pu with thermal neutrons at ILL (Grenoble). In the latter case, the detection is based on time correlation measurements between fission fragments detected by the LOHENGRIN mass spectrometer and γ‐rays or conversion electrons from the isomer decay. It was found that three shapes coexist in the odd 97Sr and 99Zr and two shapes coexist in the odd‐odd 96Rb. A simple explanation of the shape‐coexistence mechanism is proposed. It is based upon the Nilsson diagram and stresses the fundamental importance of the unique parity states.
Zhu Shun-quan - One of the best experts on this subject based on the ideXlab platform.
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Signature Inversion in Odd-Odd Nuclei in the Mass Region A 100 and the Influence of the Triaxial Shape
Journal of Shanghai Teachers University, 2003Co-Authors: Zhu Shun-quanAbstract:The model of an axially symmetric rotor plus two quasi-particles for the Signature Inversion (SI) in Odd-Odd Nuclei is generalized to the calculation of two Odd-Odd Nuclei l02Rh and 98Rh in the mass region A =100. The triaxial deformation is then introduced. The calculation result shows that the possible SI mechanism (i. e. , the competition between the n - p interaction and the coriolis force in low K space) is also appropriate for Odd-Odd Nuclei in the A = 100 region. A triaxial shape can improve the vibrational property of the rotational spectra remarkably.
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CALCULATION OF YRAST BANDS FOR ODD ODD Nuclei IN A =80 REGION
Acta Physica Sinica, 1999Co-Authors: Wen Jia-yan, Zheng Ren-rong, Zhu Shun-quanAbstract:Abstract The yrast bands of odd odd Nuclei in A =80 region are calculated by using the axial rotor plus two quasipaticles model. The results coincide with the experimental data and the point of signature inversion is reproduced accurately.
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Two quasiparticles plus rotor model calculation for Odd-Odd Nuclei in the A = 160 region
Physical Review C, 1997Co-Authors: Zheng Ren-rong, Zhu Shun-quan, Pu YunweiAbstract:The axially symmetric rotor plus quasiparticle model for an odd nucleus is generalized to the Odd-Odd nucleus and special attention is paid to the model basis accounting for {gamma} vibration perturbation around axial symmetry. The method presented in this paper is used for a number of realistic Nuclei in the A=160 mass region. Two slightly different calculation schemes are put into practice. The first calculation gives results in qualitative agreement with experiments and the second calculation provides remarkable improvements to the first. A possible explanation of the mechanism for signature inversion of Odd-Odd Nuclei is discussed. {copyright} {ital 1997} {ital The American Physical Society}
Naoki Tajima - One of the best experts on this subject based on the ideXlab platform.
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Roles of triaxiality and residual interaction in signature inversions of A ∼ 130 Odd-Odd Nuclei
Nuclear Physics A, 1994Co-Authors: Naoki TajimaAbstract:Abstract Rotational bands with (π h 11 2 ) 1 (ν h 11 2 ) 1 configurations are studied using a particle-rotor model in which a proton and a neutron quasiparticle interacting through a zero-range force are coupled with a triaxial rotor. It is shown for 124Cs that one can reproduce the signature dependence of the energy and the B ( M 1) B( E 2) ratio best when one takes into account γ-deformations with irrotational-flow moment of inertia in addition to the proton-neutron interaction proposed by Semmes and Ragnarsson. Including both effects, a systematic calculation of signature splittings is performed for Cs, La isotopes and N = 75 isotones to be compared with experiments. The deficiencies of the cranking model are also discussed concerning its applicability to signature-inversion phenomena in Odd-Odd Nuclei.
