The eXTP (enhanced X-Ray Timing and Polarimetry) mission is a Chinese science space mission developed in collaboration with many international countries. Devoted to observations in the X-ray band, with imaging, spectroscopic, timing and polarimetry capabilities, is now entering phase B. The payload includes 9 Spectroscopic Focusing Array (SFA) and 4 Polarimetry Focusing Array (PFA) telescopes. The SFA telescopes, equipped with SDDs, have a spatial resolution of 1 arcmin, while the PFA telescopes, equipped with imaging gas pixel photoelectric polarimeters, have a spatial resolution of 30 arcsec. Both optics work in the 0.5-10 keV range with a focal length of 5.25 m and a field of view of 12 arcmin. The technology used for the optics production is Nickel electroforming from super-polished mandrels, like many previous successful X-ray missions. The reflecting coating is a double layer Au+C, which ensures optimal response at high and low energies. The PFA and SFA have the same optical design, in order to minimize the number of mandrels to be produced. In this paper, we present the optical design of these telescopes assisted with raytracing and a preliminary concept for the mechanical design supported by FEM simulation.
The Einstein Probe (EP) is a small satellite dedicated to time-domain astronomy to monitor the sky in the soft X-ray band. It is a mission led by the Chinese Academy of Sciences and developed in its space science programme with international collaboration. Its wide-field imaging capability is achieved by using established technology of the micro-pore lobster-eye X-ray focusing optics. Complementary to this is deep X-ray follow-up capability enabled by a Wolter-I type X-ray telescope. EP is also capable of fast transient alerts triggering and downlink, aiming at multi-wavelength follow-up observations by the world-wide community. EP will enable systematic survey and characterisation of high-energy transients at unprecedented sensitivity, spatial resolution, grasp and monitoring cadence. Its scientific goals are mainly concerned with discovering new or rare types of transients, including tidal disruption events, supernova shock breakouts, high-redshift GRBs, and of particular interest, electromagnetic sources of gravitational wave events.
The Hard X-ray Modulation Telescope (HXMT or also dubbed as Insight-HXMT) is China’s first astronomical satellite. It was launched on 15th June 2017 in JiuQuan, China and is currently in service smoothly. It was designed to perform pointing, scanning and gamma-ray burst (GRB) observations and, based on the Direct Demodulation Method (DDM), the image of the scanned sky region can be reconstructed. Here we introduce the mission and its progresses in aspects of payload, core sciences, ground calibration/facility, ground segment, data archive, software, in-orbit performance, calibration, background model, observations and preliminary results.
The Medium Energy X-ray Telescope (ME), covering 5-30 keV, is one of the three main payloads of the Hard X-ray Modulation Telescope (HXMT). ME adopts an array of Si-PIN detectors. The detection area of one pixel is 56.25 mm<sup>2</sup> , and the total detection area is 952 cm<sup>2</sup> . The ME has a large active area while the pixel size is smaller. So the front-end electronics and forming electronics are realized by Application Specific Integrated Circuit (ASIC) chips. In this paper, we will describe the matching design of ME Si-PIN detector and ASIC, and the performance of the design. The energy response, temperature response, and dead time of a Two-Pixels Si-PIN detectors with the simplest readout electronics which is similar with ME, were tested on the Max Planck Institute for Extraterrestrial Physics PANTER X-ray test facility at Neuried by Munchen (Germany). The overall performance is quite similar to what was expected.