A new X-ray microcalorimeter based on a pixelated TES array

Abstract

We are developing a new x-ray microcalorimeter based on superconducting transition edge sensors (TES) as an imaging sensor. This device has ten pixelated transition edge sensors with Iridium superconductive films. When a constant bias voltage is applied to all pixels, each pixel is operated at slightly different equilibrium temperature. This arises from the different thermal responses between pixels, so that response signal shapes would vary according to the position of the incident x-ray. We have fabricated a prototype of the pixelated array and examined its performance. The position dependency measurements by scanning the collimated x-ray over the device have successfully shown that the device is able to resolve its pixel position. The energy resolution of a test device was 13.1 eV (FWHM) for 3 keV x-rays.