Simulations of background sources in AMoRE-I experiment

Abstract The first phase of the Advanced Mo-based Rare process Experiment (AMoRE-I), an experimental search for neutrinoless double beta decay ( 0 ν β β ) of 100 Mo in calcium molybdate ( 40 Ca 100 MoO 4 ) crystal using cryogenic detection techniques, is in preparation at the YangYang underground laboratory (Y2L) in Korea. A GEANT4 based Monte Carlo simulation was performed for the first-phase AMoRE detector and shield configuration. Background sources such as 238 U, 232 Th, 235 U, and 210 Pb from inside the crystals, surrounding materials, outer shielding walls of the Y2L cavity were simulated. The estimated background rate in the region of interest was estimated to be 1.5 × 10 − 3 counts/keV/kg/yr (ckky). The effects of random coincidences between backgrounds and two-neutrino double beta decays of 100 Mo as a potential background source were estimated to be 2.3 × 10 − 4 ckky.