Speaker
Description
The CUPID experiment aims to search for neutrinoless double beta ($0\nu2\beta$) decay of $^{100}$Mo using enriched scintillating lithium molybdate (LMO) crystals operated as cryogenic bolometers with simultaneous phonon and light readout. This dual-readout approach provides effective suppression of alpha-induced background in the region of interest by exploiting the reduced scintillation light yield of alpha interactions. CUPID will consist of 1596 LMO crystals coupled to 1710 light detectors, placing stringent requirements on sensor performance and readout scalability. The relatively high rate of the two-neutrino double beta ($2\nu2\beta$) decay of $^{100}$Mo leads to a non-negligible background from event pile-up, motivating the development of fast light detectors with excellent energy resolution. Transition edge sensors (TES) represent a promising solution to meet these requirements. To enable their large-scale deployment, an efficient and scalable readout architecture is essential. Frequency-domain multiplexing (fMUX) allows the simultaneous readout of multiple TES channels while reducing wiring complexity and cryogenic thermal load. In this poster, we present the implications of fMUX readout for $0\nu2\beta$ searches and report on the current status of TES light detector development for CUPID and future ton-scale experiments.