An Electro-thermal Response Model of CUORE Bolometers

CUORE (Cryogenic Underground Observatory for Rare Events) is an ongoing tonne-scale search for 0νββ decay in ¹³⁰Te implementing Neutron Transmutation Doped (NTD) Germanium as thermistors. The experiment contains a total of 741 kg TeO₂ crystals and operates at a cryogenic temperature of around 10 mK. While there have been efforts in modeling the electro-thermal system in the precursor experiment CUORE-0, it is essential to build and test another one for CUORE to further understand key thermal interfaces that determine the quality of the pulse signal. We present an idealized electro-thermal pulse response model using the NTD Ge Voltage-Current data in thermal equilibrium. The model is fitted to normalized real-time pulses in 78 CUORE channels for validation and extraction of interested parameter values, such as crystal-NTD thermal conductance and crystal-heatsink thermal conductance. The application of the analytical response curve in the optimal filter for each channel is expected to further improve the current energy resolution of 8 keV in the region of interest. A similar model can be adopted in future detector R&D of CUORE Upgrade with Particle Identification.