Collective properties of the odd-mass I nuclei: /sup 117,119,121/I

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

DOI:https://doi.org/10.1103/PhysRevC.26.1101· OSTI ID:6710823

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

The high-spin states of /sup 117,119,121/I have been investigated by in-beam ..gamma..-ray spectroscopy via the /sup A/Sn(/sup 6/Li,3n)/sup A/+3I reactions to study the collective properties of the odd-mass I isotopes. A similar study of /sup 123,125,127/I is reported in the preceding paper. Two collective features have been observed: ..delta..J = 1 bands built on low-lying (9/2)/sup +/ proton-hole states and ..delta..J = 2 bands built on (11/2)/sup -/, (7/2)/sup +/, and (5/2)/sup +/ quasiproton states. The ..delta..J = 2 energy spacings for the (11/2)/sup -/ bands decrease significantly relative to those for the ground-state bands of the Te core nuclei as A decreases, but not for the (7/2)/sup +/ and (5/2)/sup +/ ..delta..J = 2 bands. This unexpected decrease can be explained in a generalized seniority scheme. The systematic properties of the ..delta..J = 2 bands for all of the odd-mass I isotopes are summarized. These collective properties are examined in terms of both the microscopic and phenomenological approaches. Pulsed-beam-..gamma.. measurements yielded mean lifetimes of tau = 17.5 +- 1.0, 41.5 +- 1.5, and 13.5 +- 0.5 ns for the (9/2)/sup +/ proton-hole states in /sup 117,119,121/I, respectively. These values imply hindrances of approx.10/sup 4/ relative to M1 Weisskopf estimates for the transitions to the (7/2)/sup +/ quasiproton states. A spin rotation measurement yielded a g factor for the (9/2)/sup +/ isomer in /sup 119/I of g = 1.21 +- 0.08. Another isomer with a mean life of tau = 13 +- 2 ..mu..s was observed at 2377 keV in /sup 121/I.

• Research Organization: Department of Physics, State University of New York, Stony Brook, New York 11794
• OSTI ID: 6710823
• 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 MOMENTUM
BARYONS
BETA DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
CHARGED-PARTICLE REACTIONS
COINCIDENCE SPECTROMETRY
COLLECTIVE MODEL
COMPOUND-NUCLEUS REACTIONS
ELECTRON CAPTURE RADIOISOTOPES
ELEMENTARY PARTICLES
ENERGY LEVELS
FERMIONS
GAMMA SPECTROSCOPY
HADRONS
HEAVY ION REACTIONS
HIGH SPIN STATES
HOURS LIVING RADIOISOTOPES
INTERMEDIATE MASS NUCLEI
IODINE 117
IODINE 119
IODINE 121
IODINE ISOTOPES
ISOTOPES
LIFETIME
LITHIUM 6 REACTIONS
MATHEMATICAL MODELS
MINUTES LIVING RADIOISOTOPES
MULTIPOLARITY
NEUTRONS
NUCLEAR MODELS
NUCLEAR REACTIONS
NUCLEI
NUCLEONS
ODD-EVEN NUCLEI
PARITY
PARTICLE PROPERTIES
PARTICLE-HOLE MODEL
RADIOISOTOPES
SPECTROSCOPY
SPIN
TIME DEPENDENCE