Status of vibrational structure inNi62

Measurements consisting of γ-ray excitation functions and angular distributions were performed using the (n,n ′ γ) reaction on Ni62. The excitation function data allowed us to check the consistency of the placement of transitions in the level scheme. From γ-ray angular distributions, the lifetimes of levels up to ~3.8 MeV in excitation energy were extracted with the Doppler-shift attenuation method. The experimentally deduced values of reduced transition probabilities were compared with the predictions of the quadrupole vibrator model and with large-scale shell model calculations in the fp shell configuration space. Two-phonon states were found to exist with some notable deviation from the predictions of the quadrupole vibrator model, but no evidence for the existence of three-phonon states could be established. Z=28 proton core excitations played a major role in understanding the observed structure. © 2011 American Physical Society.

[1]  P. Garrett,et al.  CORRIGENDUM: On the robustness of surface vibrational modes: case studies in the Cd region On the robustness of surface vibrational modes: case studies in the Cd region , 2010 .

[2]  P. Garrett,et al.  Breakdown of vibrational motion in the isotopes {sup 110-116}Cd , 2008 .

[3]  S. Mukhopadhyay,et al.  Pauli blocking in the low-lying, low-spin states ofPr141 , 2008 .

[4]  B. A. Brown,et al.  Z = 50 shell gap near 100Sn from intermediate-energy Coulomb excitations in even-mass 106-112Sn isotopes. , 2006, Physical review letters.

[5]  B. A. Brown,et al.  Shell model analysis of the Ni-56 spectrum in the full pf model space , 2005 .

[6]  S. Yates.  Mixed-symmetry states in weakly deformed nuclei from (n,n’γ) reaction studies , 2005 .

[7]  N. Stone.  Table of Nuclear Magnetic Dipole and Electric Quadrupole Moments , 2005 .

[8]  B. A. Brown,et al.  Shell-model description of neutron-rich pf-shell nuclei with a new effective interaction GXPF 1 , 2005 .

[9]  B. A. Brown,et al.  Effective interaction for pf-shell nuclei , 2002, nucl-th/0205033.

[10]  J. Gerber,et al.  Measurements of g factors and lifetimes of low lying states in 58-64Ni and their shell model implications , 2001 .

[11]  C. Reich,et al.  Regular ArticleNuclear Data Sheets for A = 161☆ , 2000 .

[12]  P. Garrett,et al.  Nuclear Structure Studies With the Inelastic Neutron Scattering Reaction and Gamma-Ray Detection , 2000, Journal of research of the National Institute of Standards and Technology.

[13]  G. Molnár,et al.  Analysis of Doppler-shift attenuation measurements performed with accelerator-produced monoenergetic neutrons , 1996 .

[14]  Chan,et al.  Two-proton transfer reactions on even Ni and Zn isotopes. , 1990, Physical review. C, Nuclear physics.

[15]  P. Tikkanen,et al.  TRANSITION PROBABILITY FROM THE GROUND TO THE FIRST-EXCITED 2+ STATE OF EVEN–EVEN NUCLIDES , 2001 .

[16]  O. Karban,et al.  Spectroscopy of 62Ni with the 61Ni(d, p) reaction , 1981 .

[17]  R. Julin,et al.  High-resolution study of E0 internal pair decay of excited 0+ states in 58,60,62Ni , 1981 .

[18]  A. Nathan,et al.  Yrast decay schemes from heavy-ion + /sup 48/Ca fusion-evaporation reactions: IV: /sup 53/Cr, /sup 54/V, /sup 62/Co, and /sup 61hyphen63/Ni , 1978 .

[19]  H. Ohnuma,et al.  Lifetime Measurements of Excited States in 62 Ni , 1978 .

[20]  H. Bolotin,et al.  Study of the level structure of 62Ni , 1978 .

[21]  J. Sunier,et al.  Correspondence between. cap alpha. -transfer and two-proton and two-neutron transfer reactions to the nickel isotopes. [34 Mev, pairing vibrations] , 1977 .

[22]  P. Moldauer.  Evaluation of the fluctuation enhancement factor , 1976 .

[23]  K. B. Winterbon.  An analytic theory of Doppler-shift attenuation , 1975 .

[24]  H. Nann,et al.  Study of theNi64(p, t)Ni62reaction , 1975 .

[25]  E. Sheldon,et al.  Computation of total and differential cross section for compound nuclear reactions of the type (a, a), (a, a'), (a, b), (a, γ), (a, γ-γ), (a, bγ) and (a, bγ-γ) , 1973 .

[26]  M. Oyamada,et al.  CORE-EXCITED 6$sup +$ STATES IN NICKEL ISOTOPES OBSERVED WITH INELASTIC ELECTRON SCATTERING. , 1973 .

[27]  P. Glaudemans,et al.  Shell-model calculations on the nickel isotopes , 1972 .

[28]  T. Becker,et al.  The E2-M1 mixing ratio for the 2+2 → 2+1 transition in 60,62Ni , 1972 .

[29]  J. Gómez.  QUADRUPOLE VIBRATIONS IN THE NICKEL REGION: STRUCTURE OF ODD-MASS Co ISOTOPES. , 1972 .

[30]  H. Jongsma,et al.  The decay of the 62Co isomers , 1970 .

[31]  W. Michaelis,et al.  The Excited States of ⁶²Ni Studied by the (n,γ) Reaction , 1970 .

[32]  P. K. Kuroda,et al.  Decay of Co62 isomers , 1969 .

[33]  N. Auerbach.  NUCLEAR STRUCTURE OF THE NICKEL ISOTOPES. , 1967 .

[34]  S. P. Pandya,et al.  Shell model of the nickel isotopes , 1967 .

[35]  D. M. Van Patter,et al.  COMPOUND INELASTIC NUCLEON AND GAMMA-RAY ANGULAR DISTRIBUTIONS FOR EVEN-AND ODD-MASS NUCLEI , 1966 .