Transition edge-sensor multiplexing readout for CUPID-1T

The CUPID (CUORE with Upgraded Particle IDentification) experiment is a next-generation double beta decay search experiment using cryogenic calorimeters and light detectors to measure heat and light, respectively, released by an interaction. The dual channel detection allows for particle identification and thus for background rejection. However, the superimposition of events close in time, referred to as pileup, remains one of the major background contributions, in particular the one arising from the two-neutrino double beta decay process. In view of further detector upgrades, as planned for CUPID-1T, fast detectors are required to be able to discriminate this source of background and transition-edge sensors are one of the candidates that satisfy the timing requirements needed for it. To reduce the heat load coming from the foreseen ten thousand channels or more into the cryostat, whose working point is at about ten mK, and to minimize the radioactive materials around it, multiplexed readout is necessary in this configuration. This technique is being investigated in collaboration with the Lawrence Berkeley National Laboratory and UC Berkeley. The current status of the project will be presented.