@inproceedings{b3171961058c4a509e2703dda9eb5870,
title = "Developing X-ray microcalorimeters based on TiAu TES for HUBS",
abstract = "Hot Universe Baryon Surveyor (HUBS), a Chinese space mission, is proposed to find a large fraction of the so-called missing baryons, which would help us to understand more about the structure formation and evolution of the universe. Both theoretical and experimental results show that developing a highly efficient soft X-ray spectrometer over a large field of view and with a high energy resolution is the key to detect the “missing baryons”. X-ray microcalorimeters based on a transition-edge sensor (TES) array is required for HUBS, which aims to have 1 deg2 field of view (FoV) with 1' angular resolution and 2 eV energy resolution optimized around 0.6 keV. Taking the high throughput X-ray optical focusing system on HUBS into account, the TES array is designed to have 60 x 60 pixels with an area of 1 mm2 for each pixel. The microcalorimeter consists of a TES, a weak thermal link to a heat bath, and a semi-metal or normal metal absorber to increase the X-ray absorption efficiency. When an X-ray photon with a given energy is absorbed, the temperature of the absorber increase, that can be monitored by measuring the resistance change of the TES. A bilayer of a superconductor and a normal metal is used to fabricate a TES with a critical temperature (Tc) of ~100 mK. The latter is set for the required energy resolution. For HUBS, both MoCu and TiAu TES technologies are considered in its development phase. Here we will focus on TiAu TES calorimeters designed and partially fabricated at SRON for HUBS. Recent demonstration of a resolution of 2.5 eV at 5.9 keV in an AC readout at SRON for X-IFU on board of Athena illustrates the promising of this technology. However, the challenging for the HUBS array is the large pixel size. We will report the design and fabrication of prototype HUBS calorimeters.",
keywords = "BiAu absorber, HUBS, TiAu bilayer, Transition edge sensor, X-ray microcalorimeter",
author = "G. Wang and M. Bruijn and K. Nagayoshi and M. Ridder and E. Taralli and L. Gottardi and H. Akamatsu and {Den Herder}, {J. W.} and Gao, {J. R.} and W. Cui",
year = "2020",
doi = "10.1117/12.2562100",
language = "English",
series = "Proceedings of SPIE - The International Society for Optical Engineering",
publisher = "SPIE",
editor = "{den Herder}, {Jan-Willem A.} and Shouleh Nikzad and Kazuhiro Nakazawa",
booktitle = "Space Telescopes and Instrumentation 2020",
address = "United States",
note = "Space Telescopes and Instrumentation 2020: Ultraviolet to Gamma Ray ; Conference date: 14-12-2020 Through 18-12-2020",
}