Prompt and delayed spectroscopy of {sup 142}Tb using recoil-isomer tagging

Journal Article · Sun Feb 15 04:00:00 EST 2009 · Physical Review. C, Nuclear Physics

DOI:https://doi.org/10.1103/PHYSREVC.79.024318· OSTI ID:21202720

Mason, P J. R.; Cullen, D M; Kishada, A M; Rigby, S V; Varley, B J ^[1]; Scholey, C; Eeckhaudt, S; Grahn, T; Greenlees, P T; Jakobsson, U; Jones, P M; Julin, R; Juutinen, S; Ketelhut, S; Leino, M; Leppaenen, A -P; Maentyniemi, K; Nieminen, P; Nyman, M; Pakarinen, J ^[2]

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1. Schuster Laboratory, University of Manchester, Manchester M13 9PL (United Kingdom)
2. Department of Physics, University of Jyvaeskylae, FIN-40014 Jyvaeskylae (Finland)

Recoil-isomer tagging has been used to characterize the states built upon an I{sup {pi}}=8{sup +} isomer in {sup 142}Tb. High-spin states of the neutron-deficient nucleus {sup 142}Tb were populated using an {sup 54}Fe beam, accelerated onto a {sup 92}Mo target of thickness {approx}500 {mu}g/cm{sup 2} at energies of 245, 252, and 265 MeV using the K130 cyclotron at the University of Jyvaeskylae, Finland. Use of the JUROGAM target-position Ge-detector array coupled with the GREAT focal-plane spectrometer at the RITU gas-filled recoil separator has significantly increased the efficiency of the isomer-tagging technique. The rotational band built upon the I{sup {pi}}=8{sup +} isomeric state was established with isomer-tagged {gamma}-{gamma} coincidence data and angular distributions were measured for some of the more intensely populated states. Two previously unobserved bands that bypass the isomer were also established. The new data have been interpreted within the framework of the cranked-shell model. The data show good agreement with the calculated triaxial nuclear shape with {gamma}=-30 deg. for the {sup 142m2}Tb isomeric state. The B(M1)/B(E2) branching ratios, nuclear alignment, signature splitting, and reduced transition probability, B(E1), of the isomeric state have been systematically compared with those of the neighboring nuclei. These comparisons give further evidence for the {pi}h{sub 11/2} x {nu}h{sub 11/2} configuration of the isomer.

• OSTI ID: 21202720
• Journal Information: Physical Review. C, Nuclear Physics, Journal Name: Physical Review. C, Nuclear Physics Journal Issue: 2 Vol. 79; ISSN 0556-2813; ISSN PRVCAN
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ANGULAR DISTRIBUTION
BEAMS
BRANCHING RATIO
BYPASSES
COINCIDENCE METHODS
COMPARATIVE EVALUATIONS
CONFIGURATION
CYCLOTRONS
EFFICIENCY
GE SEMICONDUCTOR DETECTORS
HIGH SPIN STATES
IRON 54
ISOMERS
MEV RANGE 100-1000
MOLYBDENUM 92 TARGET
NEUTRON-DEFICIENT ISOTOPES
NUCLEAR ALIGNMENT
PROBABILITY
RECOILS
ROTATIONAL STATES
SHELL MODELS
SPECTROSCOPY
TERBIUM ISOTOPES
THICKNESS