Pulse processing in TES detectors: comparative of different short filter methods based on optimal filtering: case study for Athena X-IFU

Abstract

The X-IFU instrument to be on board the X-ray Athena Observatory is a cryogenic microcalorimeter array of TES detectors aimed at providing spatially resolved high-resolution spectroscopy. The reconstruction software will provide energy, position and arrival time of the incoming X-ray photons that produce current pulses in the detector. Different modifications of the standard optimal filtering algorithm have been compared to process pulses shorter than those considered of high resolution (those where the full length is not available due to a close pulse after them) to select the best algorithm based on energy resolution and computing performance results. We can conclude that the best approach is that of the 0-padding filtering. However further checks about its sensibility to instrumental changes (baseline, bias voltage, etc.) are required.