Skip to main content

Lund University Publications

LUND UNIVERSITY LIBRARIES

Discrete line γ-ray spectroscopy in the (50-60)ℏ spin domain of 161,162Er

Simpson, J. ; Bagshaw, A. P. ; Pipidis, A. ; Riley, M. A. ; Bentley, M. A. ; Cullen, D. M. ; Dagnall, P. J. ; Hagemann, G. B. ; King, S. L. and Laird, R. W. , et al. (2000) In Physical Review C - Nuclear Physics 62(2). p.243211-243218
Abstract

Very high spin states (I=50-60ℏ) have been observed in the transitional nuclei 161Er and 162Er using the Euroball γ-ray spectrometer. In 161Er, three bands are observed well above spin 50ℏ. In the positive parity, positive signature (+, + 1/2) band a discontinuity in the regular rotational behavior occurs at 109/2+ and a splitting into two branches occurs at 97/2- in the negative parity, positive signature (-, + 1/2) band. The ( -, - 1/2) band continues in a regular fashion to 115/2-, tentatively (119/2-). In 162Er the positive parity, even spin (+, 0) yrast band is observed to continue smoothly up to 58+ (60+) and the negative... (More)

Very high spin states (I=50-60ℏ) have been observed in the transitional nuclei 161Er and 162Er using the Euroball γ-ray spectrometer. In 161Er, three bands are observed well above spin 50ℏ. In the positive parity, positive signature (+, + 1/2) band a discontinuity in the regular rotational behavior occurs at 109/2+ and a splitting into two branches occurs at 97/2- in the negative parity, positive signature (-, + 1/2) band. The ( -, - 1/2) band continues in a regular fashion to 115/2-, tentatively (119/2-). In 162Er the positive parity, even spin (+, 0) yrast band is observed to continue smoothly up to 58+ (60+) and the negative parity, even spin (-,0) and odd spin (-,1) bands are extended from 30- to 34- and from 31- to 47- (49-), respectively. The high spin experimental spectra are compared with both a simple model involving the occupation of specific single neutron states in the absence of neutron pair correlations and with more detailed cranked Nilsson-Strutinsky calculations in which both proton and neutron pairing correlations are neglected. The very high spin domain is found to comprise a series of unpaired rotational bands. Unpaired band crossings between bands with different neutron and proton configurations are identified in 161Er. There is no evidence for aligned oblate or terminating states being close to the yrast line in 161,162Er up to spin ≈60ℏ in contrast to the lighter Er isotopes.

(Less)
Please use this url to cite or link to this publication:
author
; ; ; ; ; ; ; ; and , et al. (More)
; ; ; ; ; ; ; ; ; ; ; ; ; ; and (Less)
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Physical Review C - Nuclear Physics
volume
62
issue
2
article number
024321
pages
8 pages
publisher
American Physical Society
external identifiers
  • scopus:12944317166
ISSN
0556-2813
language
English
LU publication?
yes
id
17663737-e036-414e-9de3-57b45ab9371d
date added to LUP
2024-01-19 14:50:52
date last changed
2024-01-22 16:03:12
@article{17663737-e036-414e-9de3-57b45ab9371d,
  abstract     = {{<p>Very high spin states (I=50-60ℏ) have been observed in the transitional nuclei <sup>161</sup>Er and <sup>162</sup>Er using the Euroball γ-ray spectrometer. In <sup>161</sup>Er, three bands are observed well above spin 50ℏ. In the positive parity, positive signature (+, + 1/2) band a discontinuity in the regular rotational behavior occurs at 109/2<sup>+</sup> and a splitting into two branches occurs at 97/2<sup>-</sup> in the negative parity, positive signature (-, + 1/2) band. The ( -, - 1/2) band continues in a regular fashion to 115/2<sup>-</sup>, tentatively (119/2<sup>-</sup>). In <sup>162</sup>Er the positive parity, even spin (+, 0) yrast band is observed to continue smoothly up to 58<sup>+</sup> (60<sup>+</sup>) and the negative parity, even spin (-,0) and odd spin (-,1) bands are extended from 30<sup>-</sup> to 34<sup>-</sup> and from 31<sup>-</sup> to 47<sup>-</sup> (49<sup>-</sup>), respectively. The high spin experimental spectra are compared with both a simple model involving the occupation of specific single neutron states in the absence of neutron pair correlations and with more detailed cranked Nilsson-Strutinsky calculations in which both proton and neutron pairing correlations are neglected. The very high spin domain is found to comprise a series of unpaired rotational bands. Unpaired band crossings between bands with different neutron and proton configurations are identified in <sup>161</sup>Er. There is no evidence for aligned oblate or terminating states being close to the yrast line in <sup>161,162</sup>Er up to spin ≈60ℏ in contrast to the lighter Er isotopes.</p>}},
  author       = {{Simpson, J. and Bagshaw, A. P. and Pipidis, A. and Riley, M. A. and Bentley, M. A. and Cullen, D. M. and Dagnall, P. J. and Hagemann, G. B. and King, S. L. and Laird, R. W. and Lisle, J. C. and Shepherd, S. and Smith, A. G. and Törmänen, S. and Afanasjev, A. V. and Ragnarsson, I.}},
  issn         = {{0556-2813}},
  language     = {{eng}},
  number       = {{2}},
  pages        = {{243211--243218}},
  publisher    = {{American Physical Society}},
  series       = {{Physical Review C - Nuclear Physics}},
  title        = {{Discrete line γ-ray spectroscopy in the (50-60)ℏ spin domain of <sup>161,162</sup>Er}},
  volume       = {{62}},
  year         = {{2000}},
}