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

Title: High spin spectroscopy of near spherical nuclei: Role of intruder orbitals

Abstract

High spin states of nuclei in the vicinity of neutron shell closure N = 82 and proton shell closure Z = 82 have been studied using the Clovere Ge detectors of Indian National Gamma Array. The shape driving effects of proton and neutron unique parity intruder orbitals for the structure of nuclei around the above shell closures have been investigated using light and heavy ion beams. Lifetime measurements of excited states in {sup 139}Pr have been done using pulsed-beam-γ coincidence technique. The prompt spectroscopy of {sup 207}Rn has been extended beyond the 181μs 13/2{sup +} isomer. Neutron-rich nuclei around {sup 132}Sn have been produced from proton induced fission of {sup 235}U and lifetime measurement of low-lying states of odd-odd {sup 132}I have been performed from offline decay.

Authors:
; ;  [1];  [2]; ; ;  [3];  [4];  [5]
  1. Variable Energy Cyclotron Centre, 1/AF Bidhan Nagar, Kolkata - 700064 (India)
  2. Fakir Chand College, Diamond Herbour, West Bengal (India)
  3. Radiochemistry Division, Variable Energy Cyclotron Centre, BARC, Kolkata - 700064 (India)
  4. Variable Energy Cyclotron Centre, 1/AF Bidhan Nagar, Kolkata - 700064, India and Saha Institute of Nuclear Physics, Kolkata-700064 (India)
  5. Variable Energy Cyclotron Centre, 1/AF Bidhan Nagar, Kolkata - 700064, India and Institut für Kernphysik, Technische Universität Darmstadt, Schlossgartenstrasse 9, 64289 Darmstadt (Germany)
Publication Date:
OSTI Identifier:
22308426
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; EXCITED STATES; GE SEMICONDUCTOR DETECTORS; HEAVY IONS; HIGH SPIN STATES; IODINE 132; ISOMERS; NEUTRON-RICH ISOTOPES; NEUTRONS; NUCLEAR STRUCTURE; PRASEODYMIUM 139; RADON 207; SPECTROSCOPY; SPIN; TIN 132; URANIUM 235

Citation Formats

Bhattacharyya, S., Bhattacharjee, T., Mukherjee, G., Chanda, S., Banerjee, D., Das, S. K., Guin, R., Gupta, S. Das, and Pai, H.. High spin spectroscopy of near spherical nuclei: Role of intruder orbitals. United States: N. p., 2014. Web. doi:10.1063/1.4893265.
Bhattacharyya, S., Bhattacharjee, T., Mukherjee, G., Chanda, S., Banerjee, D., Das, S. K., Guin, R., Gupta, S. Das, & Pai, H.. High spin spectroscopy of near spherical nuclei: Role of intruder orbitals. United States. doi:10.1063/1.4893265.
Bhattacharyya, S., Bhattacharjee, T., Mukherjee, G., Chanda, S., Banerjee, D., Das, S. K., Guin, R., Gupta, S. Das, and Pai, H.. Thu . "High spin spectroscopy of near spherical nuclei: Role of intruder orbitals". United States. doi:10.1063/1.4893265.
@article{osti_22308426,
title = {High spin spectroscopy of near spherical nuclei: Role of intruder orbitals},
author = {Bhattacharyya, S. and Bhattacharjee, T. and Mukherjee, G. and Chanda, S. and Banerjee, D. and Das, S. K. and Guin, R. and Gupta, S. Das and Pai, H.},
abstractNote = {High spin states of nuclei in the vicinity of neutron shell closure N = 82 and proton shell closure Z = 82 have been studied using the Clovere Ge detectors of Indian National Gamma Array. The shape driving effects of proton and neutron unique parity intruder orbitals for the structure of nuclei around the above shell closures have been investigated using light and heavy ion beams. Lifetime measurements of excited states in {sup 139}Pr have been done using pulsed-beam-γ coincidence technique. The prompt spectroscopy of {sup 207}Rn has been extended beyond the 181μs 13/2{sup +} isomer. Neutron-rich nuclei around {sup 132}Sn have been produced from proton induced fission of {sup 235}U and lifetime measurement of low-lying states of odd-odd {sup 132}I have been performed from offline decay.},
doi = {10.1063/1.4893265},
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}
}
  • Collective band structures have been observed in the neutron-deficient /sup 137/Sm nucleus by means of the /sup 104/Pd(/sup 37/Cl,/ital p/3/ital n/..gamma..) reaction. At lowspins, the yrast band, built on the ..nu../ital h//sub 11/2/(514)9/2/sup /minus// Nilsson orbital, exhibits a large signaturesplitting (/similar to/100 keV) consistent with a significant triaxial shape(..gamma../similar to//minus/20/degree/). At higher spins, two sidebands were observed whichare characterized by strong ..delta../ital I/=1 transitions and a lack ofsignature splitting. These band structures contain rotationally alignedlower-midshell /ital h//sub 11/2/ protons which drive the nucleustowards the prolate (..gamma..=0/degree/) shape. In addition, a decoupled bandwas observed built on an /ital I//sup ..pi../= (17/2/supmore » +/)state. This band reveals a 50% increase in the dynamic moment of inertiaconsistent with an enhanced quadrupole deformation (..beta../similar to/0.35),and is believed to be built on the ..beta..-driving..nu../ital i//sub 13/2/ (660)1/2/sup +/single-quasiparticle state, intruding from two harmonic oscillator shellsabove. The ..beta..-driving properties of this orbital represent an importantmechanism in the evolution of enhanced nuclear deformation in this region. Theresults are compared to those of the /ital N/=75 /sup 133/Ce,/sup 135/Nd, and /sup 139/Gd isotones.« less
  • We perform a systematic theoretical analysis of fully-aligned, high-spin f{sub 7/2}{sup n} seniority isomers and d{sub 3/2}{sup -1}f{sub 7/2}{sup n+1} intruder states in the A{approx}44 nuclei from the lower-fp shell. The configuration-interaction calculations, based on the nuclear shell model, are performed in the full sdfp configuration space allowing 1p-1h cross-shell excitations. The density functional theory calculations are carried out within the self-consistent Hartree-Fock approach with the Skyrme energy functional that reproduces empirical Landau parameters. While there is a nice agreement between experimental and theoretical relative energies of fully-aligned states in N>Z nuclei, this is no longer the case for themore » N=Z systems. The remaining deviation from the data is attributed to the isoscalar proton-neutron correlations. It is also demonstrated that the Coulomb corrections at high spins noticeably depend on the choice of the energy density functional.« less
  • The phenomenon of identical bands is studied by analyzing the distributions of fractional changes in the dynamical moments of inertia of pairs of bands in superdeformed (SD) nuclei. These distributions are found to exhibit a peak with a centroid at nearly zero. Their widths increase in going from the SD bands in the mass {ital A}{approximately}150, to the SD bands in the mass {approximately}190, and to the normally deformed bands in the rare-earth region. Consequently, there exists a significant excess of identical bands in SD nuclei compared to the normally-deformed nuclei at low spins. This difference may be attributed tomore » the weaker pairing correlations and the stabilizing role of intruder orbitals on the structures of SD bands. {copyright} {ital 1996 The American Physical Society.}« less
  • Shell-model calculations for 58Cu and 64Ge in the pf5/2g9/2 model space using a realistic interaction are reported and compared to those generated using an appropriately renormalized counterpart of the interaction in the truncated pf5/2 subspace. The results suggest that reliable computations can be performed in a space that does not explicitly include the intruder level so long as the interaction as well as the transition operators are renomalized appropriately.