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Microstructure Analysis of Bismuth Absorbers for Transition-Edge Sensor X-ray Microcalorimeters

Journal Article · · Journal of Low Temperature Physics

Given its large X-ray stopping power and low specific heat capacity, bismuth (Bi) is a promising absorber material for X-ray microcalorimeters and has been used with transition-edge sensors (TESs) in the past. However, distinct X-ray spectral features have been observed in TESs with Bi absorbers deposited with different techniques. Evaporated Bi absorbers are widely reported to have non-Gaussian low-energy tails, while electroplated ones do not show this feature. In this study, we fabricated Bi absorbers with these two methods and performed microstructure analysis using scanning electron microscopy and X-ray diffraction microscopy. The two types of material showed the same crystallographic structure, but the grain size of the electroplated Bi was about 40 times larger than that of the evaporated Bi. This distinction in grain size is likely to be the cause of their different spectral responses.

OSTI ID:
22809877
Journal Information:
Journal of Low Temperature Physics, Journal Name: Journal of Low Temperature Physics Journal Issue: 3-4 Vol. 193; ISSN JLTPAC; ISSN 0022-2291
Country of Publication:
United States
Language:
English

References (1)

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