Collective properties of the odd-mass I nuclei: /sup 123,125,127/I

Journal Article · Wed Sep 01 04:00:00 EDT 1982 · Phys. Rev. C; (United States)

DOI:https://doi.org/10.1103/PhysRevC.26.1089· OSTI ID:6699916

Shroy, R E; Gordon, D M; Gai, M; Fossan, D B; Gaigalas, A K

The high-spin states of /sup 123,125,127/I have been investigated via the /sup A/Sn(/sup 6/Li,3n)/sup A/+3I reactions to study the collective properties of the odd-mass I isotopes. In-beam measurements of ..gamma..-ray excitations, ..gamma..-..gamma.. coincidences, ..gamma..-ray angular distributions, and pulsed beam-..gamma.. timing were performed with Ge detectors to determine level energies, decay schemes, ..gamma..-ray multipolarities, J/sup ..pi../ assignments, and lifetime information. A similar study of the /sup 117,119,121/I isotopes is reported in the following paper. Two collective features have been identified in these odd-mass I nuclei. Systematic ..delta..J = 1 bands built on low-lying (9/2)/sup +/ proton-hole (4p-1h) states were observed. The (9/2)/sup +/ bandheads, that involve the excitation of a 1g/sub 9/2/ proton across the Z = 50 shell, drop to very low energies near the middle of the neutron shell. The properties of the (9/2)/sup +/ proton-hole states for all of the odd-mass I isotopes are presented and related to the systematic information for the proton-hole states in the entire Z> or =50 transition region. Systematic ..delta..J = 2 bands built on (11/2)/sup -/ (1h/sub 11/2/ quasiproton) states, on (7/2)/sup +/ (1g/sub 7/2/ quasiproton) states, and on (5/2)/sup +/ (2d/sub 5/2/ quasiproton) states were also observed. The ..delta..J = 2 band spacings generally follow the spacings of the Te-core ground-state bands with the exception of the (11/2)/sup -/ ..delta..J = 2 bands, for which the spacings decrease significantly relative to those for the Te cores as A decreases. These systematic properties are discussed in terms of several theoretical approaches to the onset of collectivity in transitional nuclei. An isomer at 2660 keV in /sup 123/I was observed to have a mean lifetime tau = 38 +- 3 ns.

• Research Organization: Department of Physics, State University of New York, Stony Brook, New York 11794
• OSTI ID: 6699916
• Journal Information: Phys. Rev. C; (United States), Journal Name: Phys. Rev. C; (United States) Vol. 26:3; ISSN PRVCA
• Country of Publication: United States
• Language: English

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73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ANGULAR DISTRIBUTION
ANGULAR MOMENTUM
BARYONS
BETA DECAY RADIOISOTOPES
CHARGED-PARTICLE REACTIONS
COINCIDENCE SPECTROMETRY
COLLECTIVE MODEL
COMPOUND-NUCLEUS REACTIONS
DAYS LIVING RADIOISOTOPES
DISTRIBUTION
ELECTRON CAPTURE RADIOISOTOPES
ELEMENTARY PARTICLES
ENERGY LEVELS
FERMIONS
GAMMA SPECTROSCOPY
HADRONS
HEAVY ION REACTIONS
HIGH SPIN STATES
HOURS LIVING RADIOISOTOPES
INTERMEDIATE MASS NUCLEI
IODINE 123
IODINE 125
IODINE 127
IODINE ISOTOPES
ISOTOPES
LIFETIME
LITHIUM 6 REACTIONS
MATHEMATICAL MODELS
MULTIPOLARITY
NEUTRONS
NUCLEAR MODELS
NUCLEAR REACTIONS
NUCLEI
NUCLEONS
ODD-EVEN NUCLEI
PARITY
PARTICLE PROPERTIES
PARTICLE-HOLE MODEL
RADIOISOTOPES
SPECTROSCOPY
SPIN
STABLE ISOTOPES
TIN ISOTOPES