High-spin states in /sup 157,158/Er and /sup 158,159/Tm

Journal Article · Fri Feb 01 04:00:00 EST 1985 · Phys. Rev. C; (United States)

DOI:https://doi.org/10.1103/PhysRevC.31.421· OSTI ID:6104222

Holzmann, R; Loiselet, M; Van Hove, M A; Vervier, J

High-spin states in /sup 157,158/Er and /sup 158,159/Tm have been studied via the /sup 122/Sn(/sup 40/Ar,5,4n) and /sup 141/Pr(/sup 22/Ne,5,4n) reactions, respectively, using in-beam gamma-ray spectroscopy techniques which included ..gamma..-..gamma.. coincidence, angular correlation, angular distribution, excitation function, and multiplicity measurements. The favored (..pi.. = +, ..cap alpha.. = +(1/2)) i/sub 13/2/ neutron band in /sup 157/Er has been established up to the (53/2)/sup +/ level (h..omega.. = 0.417 MeV), and the favored (..pi.. = -, ..cap alpha.. = -(1/2)) and unfavored (..pi.. = -, ..cap alpha.. = +(1/2)) h/sub 11/2/ proton bands in /sup 159/Tm, up to the (59/2)/sup -/ (h..omega.. = 0.454 MeV) and (61/2)/sup -/ (h..omega.. = 0.480 MeV) levels, respectively, i.e., well above the range of rotational frequency h..omega.. where a second backbending has been observed in the neighboring even-even nuclei. In /sup 158/Er, the yrast levels have been observed up to 38/sup +/, and in /sup 158/Tm, up to 25/sup -/. The favored i/sub 13/2/ band of the odd-N nucleus /sup 157/Er displays a strong upbending at h..omega.. = 0.40 MeV, whereas, in the two branches of the h/sub 11/2/ yrast band of the odd-Z nucleus /sup 159/Tm, no alignment effect has been observed between h..omega.. = 0.27 and 0.48 MeV. The experimental results have been analyzed in the framework of the cranked shell model. On the basis of blocking arguments and cranked shell model calculations, the obtained results show that the second backbending in the yrast band of even-even nuclei near A = 158 is due to an h/sub 11/2/ proton alignment.

• Research Organization: Institut de Physique Nucleaire, B-1348 Louvain-la-Neuve, Belgium
• OSTI ID: 6104222
• Journal Information: Phys. Rev. C; (United States), Journal Name: Phys. Rev. C; (United States) Vol. 31:2; ISSN PRVCA
• Country of Publication: United States
• Language: English

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73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ANGULAR CORRELATION
ANGULAR DISTRIBUTION
ARGON 40 REACTIONS
BACKBENDING
BETA DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
CHARGED-PARTICLE REACTIONS
COINCIDENCE SPECTROMETRY
CORRELATIONS
CROSS SECTIONS
DATA
DISTRIBUTION
ELECTRON CAPTURE RADIOISOTOPES
ENERGY LEVELS
ERBIUM 157
ERBIUM 158
ERBIUM ISOTOPES
EVEN-EVEN NUCLEI
EVEN-ODD NUCLEI
EXCITATION FUNCTIONS
EXPERIMENTAL DATA
FUNCTIONS
GAMMA SPECTROSCOPY
H
HEAVY ION REACTIONS
HIGH SPIN STATES
HOURS LIVING RADIOISOTOPES
INFORMATION
INTERMEDIATE MASS NUCLEI
ISOTOPES
MATHEMATICAL MODELS
MINUTES LIVING RADIOISOTOPES
MULTIPLICITY
NEON 22 REACTIONS
NUCLEAR MODELS
NUCLEAR REACTIONS
NUCLEI
NUMERICAL DATA
ODD-EVEN NUCLEI
ODD-ODD NUCLEI
PRASEODYMIUM 141 TARGET
RADIOISOTOPES
RARE EARTH ISOTOPES
RARE EARTH NUCLEI
SHELL MODELS
SPECTROSCOPY
TARGETS
THULIUM ISOTOPES
TIN 122 TARGET