EP-FXT electronics development and in-orbit performance

Background The Einstein probe (EP) is an X-ray astronomical satellite dedicated to time-domain astronomy and high-energy astrophysics. Initiated at the end of 2017, it was successfully launched on January 9, 2024. The follow-up X-ray telescope (FXT) is a key payload on the EP satellite. The FXT employs PNCCD as its focal plane detector. Its electronic components include the electronic control box (EC-Box), the detector electronics boxes (DE-Box), the refrigerator controller, the movement mechanisms controller, and the temperature control instrument.
Methods The FXT conducted functional performance tests in-orbit as planned, including three operating modes of the detector, energy detection range, and energy resolution.
Results Since FXT became operational in orbit, all electronic equipment has been working stably. The FXT has an energy detection range of 0.3–10 keV, with an energy resolution of approximately 92 eV @ 1.25 keV, and an electronic noise of about 3.3 e^-.