Transition rates of high-spin states in /sup 56/Co and /sup 56/Fe: Possible coexistence of prolate- and oblate-like configurations in /sup 56/Fe. [Angular distributions and excitation functions for /sup 54/Fe(. cap alpha. ,pn) and (. cap alpha. ,2p) reactions at 20. 4 to 29. 5 MeV]

Journal Article · Fri Oct 01 04:00:00 EDT 1976 · Phys. Rev., C; (United States)

DOI:https://doi.org/10.1103/PhysRevC.14.1412· OSTI ID:7147308

Sarantites, D G; Urbon, J; Rutledge, Jr, L L

The decay properties of the high-spin states in /sup 56/Co and /sup 56/Fe have been investigated via the /sup 54/Fe(..cap alpha.., pn)/sup 56/Co*(..gamma..) and /sup 54/Fe(..cap alpha.., 2p)/sup 56/Fe*(..gamma..) reactions in the energy range 20.4 to 29.5 MeV. From measurements of excitation functions and angular distributions of individual ..gamma.. rays with a Ge(Li)--NaI(Tl) anti-Compton spectrometer, and from ..gamma gamma..-coincidence experiments, new levels in /sup 56/Co have been identified at 2282.6 (7/sup +//sub 1/), 2371.9 (6/sup +//sub 1/), 3638.0 (8/sup +//sub 1/), 4180.2 (9/sup +//sub 1/), and 5274.6 (10/sup +//sub 1/) keV with the deduced J/sup ..pi../ values in parentheses. Similarly, levels in /sup 56/Fe have been confirmed at 3388.4 (6/sup +//sub 1/), 3755.8 (6/sup +//sub 2/), 4700.6 (7/sup +//sub 1/), 5255.3 (8/sup +//sub 1/), and 5626.8 (8/sup +//sub 2/) keV, and the J/sup ..pi../ values in parentheses have been deduced. The angular distributions in conjunction with the associated attenuation factors were analyzed to yield multipole mixing ratios delta(E2/M1). The mean lifetimes tau of these states were also carefully measured by extrapolation to the detection threshold of the effective mean lifetimes extracted from Doppler-broadened line shapes obtained at four bombardment energies between 20.4 and 29.5 MeV. Values were obtained in /sup 56/Co for the following levels: 2282.6 keV (>2000 fs), 2371.9 keV (60 +- 30 fs), 3638.0 keV (80/sup +40//sub -//sub 30/ fs), 4180.2 keV (590 +- 60 fs), and 5274.6 keV (60/sup +40//sub -//sub 20/ fs); and in /sup 56/Fe values were found for levels at 3388.4 keV (>2000 fs), 3755.8 keV (180/sup +40//-/sub 30/ fs), 4700.6 keV (120 +- 40 fs), 5255.3 keV (500 +- 50 fs), and 5626.8 keV (100/sup +40/-/sub 20/ fs). For most of the transitions from the high-spin states in /sup 56/Co and /sup 56/Fe B(..lambda..) values were obtained. The results for /sup 56/Fe are compared with recent calculations based on the aligned coupling scheme. The results for /sup 56/Co are compared with other recent shell-model calculations. (AIP)

• Research Organization: Department of Chemistry, Washington University, St. Louis, Missouri 63130
• OSTI ID: 7147308
• Journal Information: Phys. Rev., C; (United States), Journal Name: Phys. Rev., C; (United States) Vol. 14:4; ISSN PRVCA
• Country of Publication: United States
• Language: English

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73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ALPHA REACTIONS
ANGULAR DISTRIBUTION
ANGULAR MOMENTUM
BARYONS
BETA DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
CHARGED-PARTICLE REACTIONS
COBALT 56
COBALT ISOTOPES
COINCIDENCE SPECTROMETRY
COMPOUND-NUCLEUS REACTIONS
CROSS SECTIONS
DAYS LIVING RADIOISOTOPES
DISTRIBUTION
ELECTROMAGNETIC RADIATION
ELECTRON CAPTURE RADIOISOTOPES
ELEMENTARY PARTICLES
ENERGY LEVELS
ENERGY RANGE
EVEN-EVEN NUCLEI
EXCITATION FUNCTIONS
FERMIONS
GAMMA RADIATION
GAMMA SPECTRA
HADRONS
INTERMEDIATE MASS NUCLEI
IONIZING RADIATIONS
IRON 54 TARGET
IRON 56
IRON ISOTOPES
ISOTOPES
LIFETIME
MEV RANGE
MEV RANGE 10-100
MIXING RATIO
MULTIPOLARITY
NEUTRONS
NUCLEAR REACTIONS
NUCLEI
NUCLEONS
ODD-ODD NUCLEI
PARITY
PARTICLE PROPERTIES
PROBABILITY
PROTONS
RADIATIONS
RADIOISOTOPES
SPECTRA
SPIN
STABLE ISOTOPES
TARGETS