Resolving γ-ray overlap of 117mSn, 117Sb, and 123mTe for cross-section measurement

Abstract

The production cross-sections of ^117mSn, ¹¹⁷Sb, and ^123mTe in α-particle induced reactions on ⁿᵃᵗSn were measured up to 50 MeV using the stacked-foil activation technique. A significant analytical challenge arose from the overlapped peak near the 159 keV γ-rays from these nuclides. This overlapped peak was resolved using a time-differential analysis that leveraged the different half-lives (¹¹⁷Sb: 2.8 h, ^117mSn: 13.6 d, ^123mTe: 119.2 d). Through γ-ray spectrometry at multiple cooling times (0.6 h to 144.9 d), a sequential subtraction method based on the activation formula was used to distinguish the overlapped peak. The resulting independent cross-sections of these ^117mSn, ¹¹⁷Sb, and ^123mTe isotopes, are in good agreement with literature data, thereby validating the method for resolving complex γ-ray interferences.