The detectors for the SFA instrument of the enhanced x-ray timing and polarimetry (eXTP) satellite mission

Abstract

Silicon drift detector modules comprising 19 cells are currently developed for five of the Spectroscopy Focusing Array (SFA) telescopes of the enhanced X-ray timing and polarimetry (eXTP) mission. The SFA-T instrument allows for fast timing (time resolution <10 µs) and good spectroscopy capabilities, i.e., an energy resolution better than 180 eV at 6 keV photon energy. The sensor, consisting of 19 hexagonally shaped cells with a total sensitive area of 5.05 cm², is connected to three high time resolution spectroscopy ASICs. This design allows for a compact layout and fast readout of the incident X-ray photon signals. The detector works in a charge-sensitive amplifier configuration of the SDD’s integrated first FET. Prototype detector modules have been developed and their performance tested. The design development for the flight detector modules has been started. The sixth SFA telescope will be equipped with a PN-CCD detector module, the same type which is also currently in use on the Einstein Probe satellite mission. It enables high spatial, energy, and time resolution, as has already been demonstrated by the eROSITA telescope array on the SRG satellite.