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Title: MICROCALORIMETER SPECTROSCOPY AT HIGH PULSE RATES: A MULTI-PULSE FITTING TECHNIQUE

Journal Article · · Astrophysical Journal, Supplement Series
; ; ; ; ; ;  [1]; ;  [2]
  1. National Institute of Standards and Technology, 325 Broadway MS 686.02, Boulder, CO 80305 (United States)
  2. National Institute of Standards and Technology, Brookhaven National Lab, Brookhaven, NY (United States)

Transition Edge Sensor microcalorimeters can measure X-ray and gamma-ray energies with very high energy resolution and high photon-collection efficiency. For this technology to reach its full potential in future X-ray observatories, each sensor must be able to measure hundreds or even thousands of photon energies per second. Current “optimal filtering” approaches to achieve the best possible energy resolution work only for photons that are well isolated in time, a requirement which is in direct conflict with the need for high-rate measurements. We describe a new analysis procedure to allow fitting for the pulse height of all photons even in the presence of heavy pulse pile-up. In the limit of isolated pulses, the technique reduces to standard optimal filtering with long records. We employ reasonable approximations to the noise covariance function in order to render this procedure computationally viable even for very long data records. The technique is employed to analyze X-ray emission spectra at 600 eV and 6 keV at rates up to 250 counts s{sup −1} in microcalorimeters having exponential signal decay times of approximately 1.2 ms.

OSTI ID:
22520148
Journal Information:
Astrophysical Journal, Supplement Series, Vol. 219, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0067-0049
Country of Publication:
United States
Language:
English