Sensitive Calorimeter based on Coupled Dielectric Resonators

A coupled microwave dielectric resonator system is under development, aimed at realizing a high resolution single X-ray photon energy detector, operating at relatively high cryogenic temperature, around 4K. Construction of the cooler system and thermal characterisation system is completed, with a demonstrated base temperature of 2.2 K. All aspects of the novel calorimeter performance have been evaluated, including demonstration of the required rapid thermal time constant of a coupled resonator, a high $df/dT$ response and promising development of a low noise microwave detection system.