Light Detection Improvement From Scintillating Crystals for Rare Event Searches

The role of low temperature detectors has become increasingly important in rare-event search experiments, such as neutrinoless double-beta decay ($0\nu \beta \beta$) and dark-matter detection. In particular, detectors employing scintillating crystals as absorbers provide a dual-channel mechanism, simultaneously measuring heat (phonons) and light (photons), thereby enabling extreme energy sensitivity and effective background reduction. We performed Monte Carlo simulations of photon propagation and absorption in a detector system designed for simultaneous detection of heat and light. The resulting light-collection efficiencies were evaluated for various detector configurations developed for the AMoRE$0\nu \beta \beta$experiment. The simulations reproduce the observed improvement in light-collection efficiency achieved in the most recent configuration compared to earlier versions. We further discuss optical parameters that can be reliably calculated, as well as those subject to large uncertainties. This approach provides a valuable framework for optimizing future detector module configurations.