Energy levels of {sup 249}Bk populated in the {alpha} decay of {sub 99}{sup 253}Es and {beta}{sup -} decay of {sub 96}{sup 249}Cm

Journal Article · Sun May 01 00:00:00 EDT 2005 · Physical Review. C, Nuclear Physics

DOI:https://doi.org/10.1103/PhysRevC.71.054305· OSTI ID:20698655

Ahmad, I; Kondev, F G; Moore, E F; Carpenter, M P; Chasman, R R; Greene, J P; Janssens, R V.F.; Lauritsen, T; Lister, C J; Seweryniak, D ^[1]; Hoff, R W; Evans, J E; Lougheed, R W ^[2]; Porter, C E; Felker, L K ^[3]

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1. Argonne National Laboratory, Argonne, Illinois 60439 (United States)
2. Lawrence Livermore National Laboratory, Livermore, California 94551 (United States)
3. Nuclear Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)

The level structure of {sup 249}Bk has been investigated by measuring the {gamma}-ray spectra of an extremely pure {sup 253}Es sample obtained by milking this nuclide from {sup 253}Cf source material produced in the High Flux Isotope Reactor at Oak Ridge National Laboratory. Additional information on the {sup 249}Bk levels was obtained from the {beta}{sup -}-decay study of {sup 249}Cm, produced by neutron irradiation of {sup 248}Cm. Using the results of the present study together with the data from previous {sup 248}Cm({alpha},t) and {sup 248}Cm({sup 3}He,d) reactions, the following single-particle states have been identified in {sup 249}Bk: 7/2{sup +}[633], 0.0 keV; 3/2{sup -}[521], 8.78 keV; 1/2{sup +}[400], 377.55 keV; 5/2{sup +}[642], 389.17 keV; 1/2{sup -}[530], 569.20 keV; 1/2{sup -}[521], 643.0 keV; 5/2{sup -}[523], 672.9 keV; and 9/2{sup +}[624], 1075.1 keV. Four vibrational bands were identified at 767.9, 932.2, 1150.7, and 1223.0 keV with tentative assignments of {l_brace}7/2{sup +} [633] x1{sup -}{r_brace}9/2{sup -}, {l_brace}7/2{sup +} [633] x 0{sup -}{r_brace}7/2{sup -}, {l_brace}7/2{sup +} [633] x 1{sup -}{r_brace}5/2{sup -}, and {l_brace}7/2{sup +} [633] x 0{sup +}{r_brace}7/2{sup +}, respectively. A band at 899.9 keV was observed in {gamma}-{gamma} coincidence measurements and given a tentative spin assignment of 3/2. It is possibly associated with a 2{sup -} phonon coupled to the ground state, with configuration {l_brace}7/2{sup +} [633] x 2{sup -}{r_brace}3/2{sup -}. Three levels at 624.3, 703.5, and 769.1 keV were assigned spins of 5/2, 7/2, and 9/2, respectively. These could be the members of the 3/2{sup +} [651] band, expected in this energy region.

• OSTI ID: 20698655
• Journal Information: Physical Review. C, Nuclear Physics, Vol. 71, Issue 5; Other Information: DOI: 10.1103/PhysRevC.71.054305; (c) 2005 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2813
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ALPHA DECAY
ALPHA PARTICLES
BERKELIUM 249
BETA DECAY
CALIFORNIUM 253
CURIUM 248
CURIUM 249
EINSTEINIUM 253
GAMMA SPECTRA
GROUND STATES
HELIUM 3
HFIR REACTOR
HIGH SPIN STATES
IRRADIATION
KEV RANGE
NEUTRONS
PARITY
PHONONS
SPIN
VIBRATIONAL STATES