Development of an X-ray transition edge sensor device with an Au/Bi absorber for the X-IFU sensor onboard Athena X-ray observatory
Istituto Nazionale di Ricerca Metrologica (INRIM)
Sala Conferenze, Palazzina M
SRON Netherlands Institute for Space Research
Athena is an ESA-lead X-ray observatory, to be launched in 2028, with the aim of high-resolution spectroscopy enabling the exploration of new horizons of science themes on the hot and energetic universe. The main sensor of the X-ray Integral Field Unit (X-IFU) is a large array of Transition Edge Sensor (TES) calorimeters designed to offer 2.5 eV spectral resolution at 6 keV with a 5” image pixel, corresponding to the calorimeter pixel size of 250 μm square. At SRON, we have been working on the development of TES devices based on superconducting TiAu bilayers to optimize the performance of a European TES array, as a backup sensor to the primary device that have been developing at NASA/GSFC.
An X-ray TES microcalorimeter consists of three components basically: an X-ray absorber made of high-quantum efficiency material(s), a sensitive thermometer that can measure a temperature rise caused by the absorbed X-ray energy, and a thermal link to a low-temperature bath. Thermal conductivity and heat capacity of the absorber are important parameter to be tuned to achieve high spectral resolution performance. An X-ray absorber consists of electroplated Bi and Au films is one of the promising candidates for the X-IFU sensor.
I will talk about fabrication details for an TiAu TES based X-ray microcalorimeter with an Au/Bi absorber. The very first characterization results of the SRON TES devices of the first generation will be also briefly presented.
Useful links: http://www.the-athena-x-ray-observatory.eu