Speaker
Description
Transition edge sensors (TES) are recognized as a key technology for cryogenic detectors requiring high sensitivity, fast response, and scalability to large numbers of channels. Within the framework of the CUPID (CUORE Upgrade with Particle IDentification) experiment, which aims to search for neutrinoless double beta decay, recent advances in TES technologies are presented, including developments of both bilayer and tungsten-based sensors. Fabrication methods, optimization strategies, and detector performance at millikelvin temperatures are reviewed, with emphasis on energy resolution, signal-to-noise ratio, and timing response relevant for particle identification and pile-up rejection. Particular attention is given to scalable readout architectures, where frequency-domain multiplexing (fMUX) is used to enable the simultaneous readout of multiple channels while reducing wiring complexity and cryogenic heat load. Results on multiplexed TES operation are discussed, including possible readout noise and its mitigation. The prospects for the integration of large TES arrays into next-generation cryogenic experiments are outlined, with relevance extending beyond neutrinoless double beta decay searches to a broad class of low-temperature rare-event experiments.