Spectroscopic performance of the electrical functional models for the eXTP SFA-T detectors

Abstract

The Spectroscopy Focusing Array (SFA) is one of the three instruments on the eXTP satellite. It consists of six telescopes plus focal plane cameras, where five are equipped with a Silicon Drift Detector (SDD) array. These five SFA-T (T stands for timing) instruments are used for observations with high time resolution (better than 10 microseconds), high throughput (dead time less than 5 % when observing a 1 Crab source), and good energy resolution (better than 180 eV at 6 keV). This paper presents the spectroscopic performance of the Electrical Functional Modules (EFM) for SFA-T that are assembled and tested at the Max Planck Institute for Extraterrestrial Physics (MPE). A focus lies on the energy resolution at the planned sensor operating temperature of -45 °C. Additionally, the use of a baffle that covers the pixel edges is studied.