Cosmogenic-neutron activation of TeO2 and implications for neutrinoless double-beta decay experiments

TL;DR

This study measures cosmogenic-neutron activation cross sections of tellurium to assess background noise in neutrinoless double-beta decay experiments like CUORE, identifying 110mAg as a significant contaminant.

Contribution

It provides new measurements of neutron activation cross sections for tellurium and evaluates their impact on background levels in double-beta decay experiments.

Findings

110mAg is a dominant background contributor.

Estimated activation background for CUORE.

Comparison with semi-empirical calculations.

Abstract

Flux-averaged cross sections for cosmogenic-neutron activation of natural tellurium were measured using a neutron beam containing neutrons of kinetic energies up to $\sim$800 MeV, and having an energy spectrum similar to that of cosmic-ray neutrons at sea-level. Analysis of the radioisotopes produced reveals that 110mAg will be a dominant contributor to the cosmogenic-activation background in experiments searching for neutrinoless double-beta decay of 130Te, such as CUORE and SNO+. An estimate of the cosmogenic-activation background in the CUORE experiment has been obtained using the results of this measurement and cross-section measurements of proton activation of tellurium. Additionally, the measured cross sections in this work are also compared with results from semi-empirical cross-section calculations.