Cosmogenic activation in the neutrinoless double-beta decay experiment CUORE

The Cryogenic Underground Observatory for Rare Events (CUORE) will search for the neutrinoless double-beta (0$\nu \beta \beta )$ decay of $^{130}$Te using an array of 988 high-resolution bolometers. Each bolometer, comprised of a TeO$_{2}$ crystal and a thermal sensor, serves as both a source and a detector. Observation of 0$\nu \beta \beta $ decay requires that all backgrounds be identified and understood. One source of background that is poorly characterized is cosmogenic neutron activation of the TeO$_{2}$ crystals. This process, which produces long-lived radioisotopes that can obscure the 0$\nu \beta \beta $ decay signal, occurs while the crystals are transported by ship from their production site in China to the detector site in Italy. Cross-section measurements in which TeO$_{2}$ targets are irradiated with a spectrum mimicking that of cosmic-ray neutrons were carried out at the Los Alamos Neutron Science Center. The resulting cross-sections have been used in a Monte Carlo simulation to estimate the cosmogenic background that will be present in CUORE.