Measurements of gamma-ray emission probabilities of ^{241, 243}Am and ²³⁹Np

Abstract

Gamma-ray emission probabilities of 241, 243 Am and 239 Np have been precisely measured with gamma-and alpha-ray spectroscopic methods. The activities of the samples were determined by measuring alpha particles using a Si semiconductor detector. Gamma rays emitted from the samples were measured with a planar type High-Purity Germanium (HPGe) detector. An efficiency curve of the HPGe detector was derived with uncertainties from 0.7% to 2.5% by combining measured efficiencies and Monte Carlo simulation. The gamma-ray emission probabilities for the major gamma rays of these nuclides were determined with uncertainties less than 1.2%.

Monte Carlo simulation-aided design of a thermal neutron generator system from 241Am-Be isotopic sources

“…The gamma rays emitted by the 241 Am-Be source are: a) 241 Am alpha decay gamma lines: 26.34 keV (2.27%) and 59.54 keV (35.64%) [25,26] b) Prompt gammas emitted in the 9 Be(α,n) 12 C reaction that takes the residual carbon nucleus to the first excited state of 4,438 keV, where the gamma/neutron ratio is 0.575 [27] Therefore, it was decided to carry out two separate simulations for the gamma radiation emitted by the 241 Am-Be source. The first one was for 26.34 and 59.54 keV lines, with relative intensities of 0.05988 and 0.94012 (note that the sum must be equal to 1).…”

Research and development for accuracy improvement of neutron nuclear data on minor actinides

“…This method was originally developed in [19]. The γ -ray emission probabilities for the major γ rays of relevant nuclides were determined with uncertainties less than 1.2% [20]. The sample amounts deduced using the efficiency and the γ -ray emission probabilities are determined with uncertainty of about 2%.…”