Count Rate Optimizations for TES Detectors at a Femtosecond X-ray Laser

• Published in: Journal of low temperature physics Vol. 199; no. 3-4; pp. 1038 - 1045
• Main Authors: Titus, C. J., Li, D., Alpert, B. K., Cho, H. -M., Fowler, J. W., Lee, S. -J., Morgan, K. M., Swetz, D. S., Ullom, J. N., Wessels, A., Irwin, K. D.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01-05-2020; Springer Nature B.V; Springer
• Subjects: Calorimeters; Characterization and Evaluation of Materials; Coherent light; Condensed Matter Physics; Energy resolution; Free electron lasers; LCLS-II; Light sources; Low temperature physics; Magnetic Materials; Magnetism; Physics; Physics and Astronomy; PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; Transition-edge sensor; X ray detectors; X ray lasers; X-ray spectroscopy; Transition-edge sensor; LCLS-II; X-ray spectroscopy
• ISSN: 0022-2291; 1573-7357
• DOI: 10.1007/s10909-020-02379-5

Transition-edge sensor microcalorimeters have found success as X-ray detectors at synchrotron light-sources, due to a unique combination of high collecting area and good energy resolution. However, the upcoming generation of free-electron lasers (FELs), such as the Linac Coherent Light Source II, is designed to deliver more than
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photons in a 100 fs pulse at a 100 kHz rate, potentially leading to severe pulse-pileup issues. We will demonstrate that, for most relevant science cases, it is possible to mitigate pulse pile-up using simple X-ray filters in a way that takes advantage of the substantial increase in X-ray flux at modern FELs.