One- and three-quasiparticle states in /sup 249/Cf populated by the electron capture decay of 1. 70-h /sup 249/Es
The level structure of /sup 249/Cf has been investigated by measuring the ..gamma.. rays and conversion electrons associated with the electron capture decay of 1.70-h /sup 249/Es. The ..gamma..-ray spectra were measured with a 2-cm/sup 2/ x 5-mm planar and a 25-cm/sup 3/ coaxial Ge(Li) detector and the conversion-electron spectra were measured with a cooled Si(Li) detector. Forty-six ..gamma.. rays were identified and multipolarities of most of the transitions were deduced. The half-life of /sup 249/Es was determined from the decay rate of the 379.5-keV photopeak and was found to be 102.2 +- 0.6 min. The logft values for the observed electron capture transitions were derived from the measured electron capture intensities. On the basis of the present work the following intrinsic states were identified: 9/2-(734), 0; 5/2+(622), 145.0; 7/2+(624), 379.5; 7/2+(613), 443.0; K..pi..=5/2-, 813.2; 9/2+(615), 1007.9; and K..pi..=7/2-, 1218.5. The 5/2- band at 813.2 keV has been interpreted as the ..gamma..-vibrational band coupled to the 9/2-(734) ground state. The 7/2- state at 1218.5 keV has been interpreted as a three-quasiparticle state with configuration )p(633)7/2+; p(521)3/2-; n(622)3/2+closing-brace/sub 7///sub 2/-. This is the first time a three-quasiparticle state in an actinide nucleus has been identified. An enhancement in the B (E3) value of the 145.0..-->..0 transition has been observed which suggests collective admixture in the 145.0-keV state. From the experimental B (E3) value the admixture (amplitude squared) of the )9/2-(734)direct-product2/sup -/closing-brace/sub 5///sub 2/+ configuration in the 145.0-keV state has been derived to be approx.29%, in excellent agreement with the results of (d,d') reaction studies. (AIP)
- Research Organization:
- Chemistry Division, Argonne National Laboratory, Argonne, Illinois 60439
- OSTI ID:
- 7278915
- Journal Information:
- Phys. Rev., C; (United States), Vol. 14:1
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
CALIFORNIUM 249
EINSTEINIUM 249
ELECTRON CAPTURE DECAY
GAMMA SPECTROSCOPY
FT VALUE
HALF-LIFE
DEUTERON REACTIONS
MEV RANGE 10-100
NEUTRONS
ACTINIDE ISOTOPES
ACTINIDE NUCLEI
ALPHA DECAY RADIOISOTOPES
BARYONS
BASIC INTERACTIONS
BETA DECAY
BETA DECAY RADIOISOTOPES
CALIFORNIUM ISOTOPES
CHARGED-PARTICLE REACTIONS
DECAY
EINSTEINIUM ISOTOPES
ELECTRON CAPTURE RADIOISOTOPES
ELEMENTARY PARTICLES
ENERGY RANGE
EVEN-ODD NUCLEI
FERMIONS
HADRONS
HEAVY NUCLEI
HOURS LIVING RADIOISOTOPES
INTERACTIONS
ISOTOPES
LEPTONIC DECAY
MEV RANGE
NUCLEAR REACTIONS
NUCLEI
NUCLEONS
ODD-EVEN NUCLEI
PARTICLE DECAY
RADIOISOTOPES
SPECTROSCOPY
WEAK INTERACTIONS
WEAK PARTICLE DECAY
YEARS LIVING RADIOISOTOPES
652023* - Nuclear Properties & Reactions
A=220 & above
Experimental- Energy Levels & Transitions- (-1987)
652022 - Nuclear Properties & Reactions
A=220 & above
Experimental- Radioactive Decay- (-1987)