Design, fabrication, and performance of a TESX-ray micro calorimeter array for STEM-EDS
村松 はるか, 永吉 賢一郎, 林 佑, 酒井 和広, 千葉 旭, 満田 和久, 山崎 典子 （JAXA）； 前畑 京介 （九大）； 原 徹 （NIMS）
Abstract:We present the design, fabrication, and performance of a superconducting TES X-ray micro calorimeter array optimized for a high-energy resolution EDS(Energy dispersive X-ray spectroscopy) on an STEM (Scanning Transmission electron microscope).The requirement for STEM-EDS system is a good energy resolution (FWHM < 10 eV) in a wide energy band (0.5~10keV ) with a maximum counting rate (> 5 kcps). In order to accommodate the high counting rate, we adopted an 8x8-format, 64-pixel array on which X-rays from the STEM will be approximately uniformly distributed by an focusing capillary optics. The transition temperature of the TES were designed to be 200 mK. The X-ray absorber is 2.5 micron thickness gold so that the detection efficiency at 10 keV is 40 %. We did all design and fabrication of the device in house. With the device we have fabricated most recently, we have confirmed that all 64 pixels are intact, that the superconducting transition temperatures of at least 7 pixels are almost uniform at about 200 mK, and that the FWHM energy resolution of one pixel is 7.8 eV at Mn K alpha (5.9 keV). Thus we consider that the device meets all the requirements although we need to wait full read out test to confirm them experimentally. In the talk, I will also describe problems we encountered during the development and how we solved them.