Optimized Transition-Edge X-ray Microcalorimeter with 2.4 eV Energy Resolution at 5.9 keV

Published

November 1, 2005

Author(s)

Joel Ullom, James A. Beall, W.Bertrand (Randy) Doriese, William Duncan, S. L. Ferreira, Gene C. Hilton, Kent D. Irwin, Carl D. Reintsema, Leila R. Vale

Abstract

We present measurements from a series of transition- edge x-ray microcalorimeters designed for optimal energy resolution. We used the geometry of the sensors to control their heat capacity and employed additional normal metal features and a perpendicular magnetic field to control the sharpness of the superconducting-to-normal transition. These degrees of control allow an optimal selection of sensor saturation energy and noise. Successive design changes improved the measured energy resolution of the sensors from 4.5 eV full-width-at-half-maximum at 5.9 keV to 2.4 eV at 5.9 keV. The sensors have an estimated quantum efficiency of 55% at 5.9 keV and measured thermal recovery times ranging from 80 to 260 microseconds. Energy-dispersive sensors with this combination of energy resolution, quantum efficiency, and speed are well matched to applications in x-ray astrophysics and terrestrial materials analysis.

Citation

Applied Physics Letters

Volume

87

Issue

19

Pub Type

Journals

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Keywords

microcalorimeter, TES, unexplained noise

Citation

Ullom, J. , Beall, J. , Doriese, W. , Duncan, W. , Ferreira, S. , Hilton, G. , Irwin, K. , Reintsema, C. and Vale, L. (2005), Optimized Transition-Edge X-ray Microcalorimeter with 2.4 eV Energy Resolution at 5.9 keV, Applied Physics Letters, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=31956 (Accessed October 27, 2025)