Open AccessUse of Transition Models to Design High Performance TESs for the LCLS-II Soft X-Ray Spectrometer
Author(s) -
Kelsey M. Morgan,
D. Becker,
Douglas A. Bennett,
W. B. Doriese,
Johnathon D. Gard,
K. D. Irwin,
Sang Jun Lee,
Dale Li,
J. A. B. Mates,
Christine G. Pappas,
D. R. Schmidt,
Charles J. Titus,
Daniel D. Van Winkle,
Joel N. Ullom,
Abigail L. Wessels,
Daniel S. Swetz
Publication year - 2019
Publication title -
ieee transactions on applied superconductivity
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.467
H-Index - 84
eISSN - 1558-2515
pISSN - 1051-8223
DOI - 10.1109/tasc.2019.2903032
Subject(s) - spectrometer , full width at half maximum , transition edge sensor , physics , linear particle accelerator , optics , resolution (logic) , pixel , laser , detector , computer science , artificial intelligence , beam (structure) , bolometer
We are designing an array of transition-edge sensor (TES) microcalorimeters for a soft X-ray spectrometer at the Linac Coherent Light Source at SLAC National Accelerator Laboratory to coincide with upgrades to the free electron laser facility. The complete spectrometer will have 1000 TES pixels with energy resolution of 0.5 eV full-width at half-maximum (FWHM) for incident energies below 1 keV while maintaining pulse decay-time constants shorter than 100 μ s. Historically, TES pixels have often been designed for a particular scientific application via a combination of simple scaling relations and trial-and-error experimentation with device geometry. We have improved upon this process by using our understanding of transition physics to guide TES design. Using the two-fluid approximation of the phase-slip line model for TES resistance, we determine how the geometry and critical temperature of a TES will affect the shape of the transition. We have used these techniques to design sensors with a critical temperature of 55 mK. The best sensors achieve an energy resolution of 0.75 eV FWHM at 1.25 keV. Building upon this result, we show how the next generation of sensors can be designed to reach our goal of 0.5 eV resolution.