Computer calculation of the ETF-TES property and development of the Ir TES for x-ray microcalorimeters

Abstract

  Static and dynamic performances of the ETF-TES are simulated by the computer calculation in order to find the optimum bias condition of the x-ray microcalorimeter. From the calculated I-V characteristic, a residual resistance of the TES should be larger than the shunt resistance in the bias circuit for a stable voltage bias. In order to obtain higher current response and to avoid distorted pulse shapes when heat pulses are induced to the microcalorimeter, the bias point should be set in smaller resistance region than that of the middle point of a superconductive transition.

  To develop a high energy resolution detector, we have been fabricating an Ir-TES x-ray microcalorimeter. Preliminary experiment to obtain the Ir film superconductive property is performed with the Ir-TES fabricated by a magnetron sputtering method. Its result is also summarized.