Electron capture decay of 238Am and electric monopole transitions in 238Pu

doi:10.1016/0375-9474(72)90987-6

Nuclear Physics A

Volume 186, Issue 3, 23 May 1972, Pages 620-640

https://doi.org/10.1016/0375-9474(72)90987-6 Get rights and content

Abstract

Mass-separated samples of $^{238} Am (T_{12} = 98 min)$ have been used to investigate the EC decay scheme of ²³⁸Am. The γ-ray and conversion electron spectra were measured with high-resolution Ge(Li) and Si(Li) spectrometers. Several electric monopole transitions were identified. The K/L ratios of the EO transitions are in agreement with the theoretical values of Church and Weneser. A γ-ray spectrum was measured in coincidence with the electron lines of the 44.1 keV transition in order to distinguish transitions going to the ground state from those terminating at the 2⁺ or 4⁺ member of the ground state band. From these data a decay scheme has been constructed. Assignments of levels already known from the β⁻ decay of ²³³⁸Np and α-decay of ²⁴²Cm have been confirmed. Several other low-spin states have been postulated to account for the observed γ-rays and conversion electrons. From log ft value considerations the ground state of ²³⁸Am has been given an assignment of ${n [743] 72^{−}; p [523] 52^{−}}1^{+}$ and the 962.8 keV level of ²³⁸Pu has been assigned to ${n [743] 72^{−}; n [622] 52^{+}}1^{−}$ . The half-life of ²³⁸Am has been measured to be 98±3 min. A 5.94 MeV α-group has been assigned to ²³⁸Am decay. The α-branching has been measured to be (1.0±0.4)×10⁻⁴%.

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^†: Work performed under the auspices of the US Atomic Energy Commission.

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Electron capture decay of 238Am and electric monopole transitions in 238Pu

Abstract

J. Inorg. Nucl. Chem.

Phys. Rev.

Nucl. Phys.

Phys. Rev.

Ph.D. thesis

Nucl. Phys.

J. Inorg. Nucl. Chem.

J. Chromat.

J. Chromat.

Phys. Rev.

Nucl. Data, sect.

Electron capture decay of ²³⁸Am and electric monopole transitions in ²³⁸Pu