Characterization of Transition Edge Sensors for Decay Energy Spectrometry

By using a superconducting transition edge sensor (TES) to measure the thermal energy of individual decay events with high energy resolution, decay energy spectrometry provides a unique fingerprint to identify each radionuclide in a sample. The proposed measurement requires optimizing the thermal parameters of the detector for use with 5 MeV scale energy deposited by alpha decay of the sample radionuclides. The thermal performance of deep-etched silicon TES chips is examined with the use of an onboard resistive heater. With known heater power and bath temperature, the thermal conductance, heat capacity, and frame temperature are calculated and compared to theory.