New measurements of gamma-ray energies and their absolute intensities from the decay of Pa-231

摘要

Accurate nuclear data for the decay of Pa-231 is highly important for non-destructive analysis in the areas of radiochronometry and nuclear forensics. However, the evaluated nuclear data for this isotope is lacking; many previous measurements have large uncertainties and only two measurements are used to determine the absolute intensities. This work presents modern measurements of the major gamma-ray emissions from the decay of Pa-231 to Ac-227 including the energies and absolute intensities. For many of these measurements, the error envelopes have been significantly decreased compared to previous measurements, while remaining in good agreement. The absolute intensity of the 283 keV reference line was measured as 0.0163(2).