Nuclear Data Sheets for A = 240

Journal Article · Wed Oct 15 04:00:00 EDT 2008 · Nuclear Data Sheets

DOI:https://doi.org/10.1016/j.nds.2008.09.002· OSTI ID:21163756

Singh, Balraj ^[1]; Browne, E ^[2]

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1. Department of Physics and Astronomy, McMaster University, Hamilton, Ontario L8S 4M1 (Canada)
2. Guest appointment at Lawrence Berkeley National Laboratory under subcontract with National Nuclear Data Center, Brookhaven National Laboratory, Upton, New York 11973-5000 (United States)

Evaluated experimental data for radioactive decays and reactions for known nuclides (U, Np, Pu, Am, Cm, Bk, Cf) of A = 240 are presented together with adopted values for level energies, {gamma}-ray energies, relative branching ratios and other nuclear properties. This revision was primarily motivated by the need for re-evaluation of absolute gamma-ray intensities from the {epsilon} decay of {sup 240}Am to {sup 240}Pu. These quantities are essential for determining precise and accurate cross-sections for the {sup 241}Am(n,2n){sup 240}Am reaction using fast neutrons (see e.g. Americium Workshop, Santa Fe, New Mexico, September 2007, 2008To06, 2007Ta01, 2006Pe14) and {sup 241}Am({gamma},n) reaction (see e.g. 2006Ri08). For {sup 240}U, the {gamma}-ray data have now become available. The data sets for {sup 244}Pu {alpha} decay to {sup 240}U; {sup 244}Cm {alpha} decay to {sup 240}Pu and {sup 244}Cf {alpha} decay to {sup 240}Cm have been adapted from evaluations by 1998Ak04 and 2003Ak04. For {sup 244}Cm decay, evaluation by 2006BeZL under the Decay Data Evaluation Project (DDEP) is also used. The {gamma}-ray data (energies and intensities) for {sup 240}Cm decay are not considered (by the evaluators) as well established. Most detailed data are available only for {sup 240}Pu. Extensive data in the second potential well are available for this nuclide together with fission isomers and several superdeformed (SD) structures. For other nuclides spectroscopic data are rather sparse in the literature; especially for the following radioactive decays: The {epsilon} decays of {sup 240}Cf, {sup 240}Bk and {sup 240}Cm; multipolarities of {gamma}-ray transitions in {sup 240}Np from {sup 240}U {beta}{sup -} decay; {gamma}-ray transitions from {sup 244}Cf {alpha} decay and %{epsilon} branch of {sup 244}Cf decay; spins and parities of excited states in {sup 240}U and multipolarities of associated {gamma}-ray transitions in {sup 240}U. This work supersedes earlier full evaluations of A = 240 published by 2004Ch64, 1984Sh34, 1977Sc13, 1970Sc39; and an evaluation published in update mode by 1990Sh04.

• OSTI ID: 21163756
• Journal Information: Nuclear Data Sheets, Journal Name: Nuclear Data Sheets Journal Issue: 10 Vol. 109; ISSN NDTSBA; ISSN 0090-3752
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ALPHA DECAY
AMERICIUM 240
AMERICIUM 241 TARGET
BERKELIUM 240
BRANCHING RATIO
CALIFORNIUM 240
CALIFORNIUM 244
CROSS SECTIONS
CURIUM 240
CURIUM 244
EINSTEINIUM 240
EVALUATED DATA
EXCITED STATES
EXPERIMENTAL DATA
FAST NEUTRONS
FISSION ISOMERS
GAMMA RADIATION
MULTIPOLARITY
NEPTUNIUM 240
NESDPS Office of Nuclear Energy Space and Defense Power Systems
NUCLEAR DATA COLLECTIONS
NUCLEAR PROPERTIES
PARITY
PLUTONIUM 240
PLUTONIUM 244
PROTACTINIUM 240
SUPERDEFORMED NUCLEI
URANIUM 240