Some new properties of 254Es and 255Es

doi:10.1016/0375-9474(67)90725-7

Nuclear Physics A

Volume 96, Issue 2, 11 April 1967, Pages 440-448

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Abstract

Alpha decay of the 39.3 h ^254mEs isomer was observed and further studies showed that this decay populates a 2⁻ excited state in ²⁵⁰Bk, but decay to the 2⁻ ground state is highly hindered. The partial alpha half-life of ^254mEs is 1.52±0.1 y. A lower limit to the spontaneous fission half-life of ²⁵⁴Es was set at 2.5 × 10⁷ y. The total decay and partial spontaneous fission half-lives of ²⁵⁴Fm were redetermined as 194.4±0.1 min and 228±1 d, respectively. The pile neutron cross sections of ²⁵³Es to produce the two isomers of ²⁵⁴Es were measured as $σ_{c} = 13 b (^{254} Es), σ_{c} = 338 b (^{254m} Es)$ . The partial alpha half-life of ²⁵⁵Es has been measured as 1.38±0.08 y and the partial spontaneous fission half-life as 2440±140 y. The rotational band structure observed in the alpha decay of ²⁵⁵Es is consistent with a $72^{+}$ spin.

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^†: Based on work performed under the auspices of the U.S. Atomic Energy Commission.

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Some new properties of 254Es and 255Es

Abstract

J. Inorg. Nucl. Chem.

J. Inorg. Nucl. Chem.

Phys. Rev.

Phys. Rev.

Phys. Rev.

Phys. Rev.

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Some new properties of ²⁵⁴Es and ²⁵⁵Es