A Study of Microcalorimeter with Dielectric Thermomete

The microcalorimeter detects a single particle of radiation by means of the temperature rise in the absorber kept at low temperature below IK. A sensitive thermometer measuring the temperature rise is an important component in the microcalorimeter. Dielectric materials whose electric capacitances depend on temperature at low temperature can be utilized for the sensitive thermometer of the microcalorimeter. The temperature dependence of the electric capacitance d(ln Cd)/dT is an important parameter for the dielectric thermometer. We have studied the dielectric thermometer made of SrTiO3 based material and carried out measurement of the electric capacitance in the temperature range from 50mK to 120mK. By using experimental values of d(ln Cd)/dT an output signal of the dielectric microcalorimeter was estimated in the detection of a 5.5 MeV α-partice.