The origin of the background radioactive isotope Xe-127 in the sample of Xe enriched in Xe-124

TL;DR

This study investigates the production mechanisms of Xe-127 isotope in xenon samples enriched in Xe-124, Xe-126, and Xe-128, to understand background sources in rare decay experiments, by measuring cross sections for muon-induced and neutron capture processes.

Contribution

It provides the first upper limit on Xe-127 production via muon-induced neutron knock-out and measures the neutron capture cross section on Xe-126, clarifying background sources in low-background experiments.

Findings

Upper limit for muon-induced Xe-127 production cross section: 0.007 barn.

Measured neutron capture cross section on Xe-126: 2.74±0.4 barn.

Results align with reference values, aiding background modeling.

Abstract

The results of investigation of Xe-127 radioactive isotope production in the xenon sample enriched in Xe-124, Xe-126, Xe-128 are presented. The isotope is supposed to be the source of the background events in the low-background experiment on search for 2K-capture of Xe-124. In this work we consider two channels of Xe-127 production: the neutron knock-out from Xe-128 nucleus by cosmogenic muons and the neutron capture by Xe-126 nucleus. For the first channel the upper limit of the cross section of Xe-127 production was found to be sigma >= 0.007 barn at 95\% C.L. For the second channel the value obtained for the cross section was found to be equal to sigma =(2.74+-0.4) barn, which coincides well, within the statistical error, with reference value.