skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Shape evolution at high spin states in Kr and Br isotopes

Abstract

The high spin states in A = 75, Kr and Br isotopes have been populated via fusion-evaporation reaction at an incident beam energy of 90 MeV. The de-exciting γ-rays were detected utilizing the Indian National Gamma Array (INGA). Lifetime of these excited high spin states were determined by Doppler-shift attenuation method. Experimental results obtained from lifetime measurement are interpreted in the frame work of projected shell-model to get better insight into the evolution of collectivity. Comparison of the calculations of the model with transitional quadrupole moments Q{sub t} of the positive and negative parity bands firmly established their configurations.

Authors:
 [1]; ; ;  [2]; ; ; ; ; ;  [3]; ;  [4];  [5];  [6];  [7];  [8]; ;  [9]
  1. Department of Pure and Physics, Guru Ghasidas Vishwavidyalaya, Bilaspur-495009 (India)
  2. Tata Institute of Fundamental Research, Mumbai-400005 (India)
  3. Inter University Accelerator Centre, New Delhi-110067 (India)
  4. Department of Physics, Shanghai Jiao Tong University, Shanghai 200240 (China)
  5. Department of Physics, University of Kashmir, Srinagar 190 006 (India)
  6. Department of Nuclear Physics, Andhra University, Visakhapatnam-530003 (India)
  7. Department of Physics and Astrophysics, University of Delhi, Delhi-110007 (India)
  8. Department of Physics, IIT Roorkee, Roorkee-247667 (India)
  9. Department of Physics, University of Allahabad, Allahabad-211001 (India)
Publication Date:
OSTI Identifier:
22308440
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 1609; Journal Issue: 1; Conference: FIG12: International conference on frontiers in gamma-ray spectroscopy 2012, New Delhi (India), 5-7 Mar 2012; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; BROMINE ISOTOPES; COMPARATIVE EVALUATIONS; DSA METHOD; HIGH SPIN STATES; KRYPTON 75; MEV RANGE 10-100; PARITY; QUADRUPOLE MOMENTS; SHELL MODELS; T QUARKS

Citation Formats

Trivedi, T., Palit, R., Naik, Z., Jain, H. C., Negi, D., Kumar, R., Singh, R. P., Muralithar, S., Pancholi, S. C., Bhowmik, R. K., Yang, Y.-C., Sun, Y., Sheikh, J. A., Raja, M. K., Kumar, S., Choudhury, D., Jain, A. K., and Mehrotra, I.. Shape evolution at high spin states in Kr and Br isotopes. United States: N. p., 2014. Web. doi:10.1063/1.4893253.
Trivedi, T., Palit, R., Naik, Z., Jain, H. C., Negi, D., Kumar, R., Singh, R. P., Muralithar, S., Pancholi, S. C., Bhowmik, R. K., Yang, Y.-C., Sun, Y., Sheikh, J. A., Raja, M. K., Kumar, S., Choudhury, D., Jain, A. K., & Mehrotra, I.. Shape evolution at high spin states in Kr and Br isotopes. United States. doi:10.1063/1.4893253.
Trivedi, T., Palit, R., Naik, Z., Jain, H. C., Negi, D., Kumar, R., Singh, R. P., Muralithar, S., Pancholi, S. C., Bhowmik, R. K., Yang, Y.-C., Sun, Y., Sheikh, J. A., Raja, M. K., Kumar, S., Choudhury, D., Jain, A. K., and Mehrotra, I.. Thu . "Shape evolution at high spin states in Kr and Br isotopes". United States. doi:10.1063/1.4893253.
@article{osti_22308440,
title = {Shape evolution at high spin states in Kr and Br isotopes},
author = {Trivedi, T. and Palit, R. and Naik, Z. and Jain, H. C. and Negi, D. and Kumar, R. and Singh, R. P. and Muralithar, S. and Pancholi, S. C. and Bhowmik, R. K. and Yang, Y.-C. and Sun, Y. and Sheikh, J. A. and Raja, M. K. and Kumar, S. and Choudhury, D. and Jain, A. K. and Mehrotra, I.},
abstractNote = {The high spin states in A = 75, Kr and Br isotopes have been populated via fusion-evaporation reaction at an incident beam energy of 90 MeV. The de-exciting γ-rays were detected utilizing the Indian National Gamma Array (INGA). Lifetime of these excited high spin states were determined by Doppler-shift attenuation method. Experimental results obtained from lifetime measurement are interpreted in the frame work of projected shell-model to get better insight into the evolution of collectivity. Comparison of the calculations of the model with transitional quadrupole moments Q{sub t} of the positive and negative parity bands firmly established their configurations.},
doi = {10.1063/1.4893253},
journal = {AIP Conference Proceedings},
number = 1,
volume = 1609,
place = {United States},
year = {Thu Aug 14 00:00:00 EDT 2014},
month = {Thu Aug 14 00:00:00 EDT 2014}
}
  • When the N=Z line approaches the proton dripline above {sup 56}Ni an increasing distortion of mirror symmetry is expected as the proton-rich partner becomes marginally bound. Urkedal and Hamamoto have considered {sup 71}Kr and suggest the distortion could lead to a different ground-state spin to its mirror partner {sup 71}Br, based on the reinterpretation of a {beta}-decay measurement. This would be a unique situation in T=1/2 nuclei. We have performed a new in-beam spectroscopic measurement of {sup 71}Br, following the {sup 40}Ca({sup 40}Ca,2{alpha}p) reaction at 160 MeV and using Gammasphere. Many new states have been found, with candidates for eightmore » Nilsson bandheads below 1 MeV. Cross-linking decays tightly constrain most of the angular momentum assignments. The {sup 71}Kr {beta}-decay data, seen in the light of this new information on {sup 71}Br, support the original ground-state assignment of {sup 71}Kr as J{sup {pi}}=5/2{sup -}, as would be normally expected for the mirror partner of J{sup {pi}}=5/2{sup -} {sup 71}Br.« less
  • Excited states in /sup 76/Kr have been investigated via the /sup 66/Zn(/sup 12/C, 2n) reaction at a beam energy of 39 MeV. Gamma-ray energies, intensities, spins, parities, and mean lives of excited states were extracted from measurements of the ..gamma.. rays which were emitted in-beam. The energies of 25 excited levels were deduced from ..gamma..-..gamma.. coincidence data, and all but three of these levels are members of bandlike structures which persist to high spin. The Doppler shift attenuation method was used to extract the lifetimes of thirteen excited levels. The E2 strengths are highly collective. The positive parity yrast bandmore » to spin (12/sup +/) has been observed with a forward bend at low spin, but with no backbending in the moment of inertia below 12/sup +/. A positive parity band with even- and odd-spin members to (6/sup +/) and (9/sup +/), respectively, has been observed and is interpreted as a ..delta..J = 1 quasigamma band. Negative-parity bands built on 5/sup -/ and (6/sup -/) levels have been observed to spins of (13/sup -/) and (12/sup -/), respectively. Finally, the first excited 0/sup +/ state and a 2/sup +/ level built on it have been identified and are assigned to a near spherical configuration which coexists with the ground state that has an unusually large deformation.« less
  • Cited by 2
  • The most commonly accepted interpretation of the light Pt isotopes invokes the coexistence and mixing with proton intruder states from above the Z = 82 shell gap. Using an alternative description, interacting boson model (IBA) calculations are performed for the Pt isotopes with a simple, single configuration, two-parameter Hamiltonian. Excellent agreement is obtained for energies and electromagnetic transition strengths over the entire isotopic chain, spanning a wide variety of structures, and suggesting that these nuclei can be described more simply without the introduction of an intruder configuration. The Pt nuclei close to midshell are found to lie close to amore » region of phase/shape coexistence.« less