The Telescope consists of detectors, collimators and shield. The star tracker is set in the center of the honeycomb. The orientations of the 18 field of views are different, with a step size of 10 degrees. The detectors, collimators, electronics, and data acquisition systems of HXMT are similar to those used in the HAPI hard X-ray telescope series in the high energy astrophysics laboratory.
Passive mode is simple, while the active mode is more effective.
As the signal processing used in the active shield takes time, the dead time in detectors, particularly in the large detectors, is quite considerable. In order to reduce the effect of dead time on detection efficiency, high Z materials have been used outside the active shield system, which is the passive shield. The sensitivities of astronomical telescopes are decided by the collective area, observing duration, detection efficiency and the background level of the detectors. To reduce background equals to increase the collective area of the observing duration. The first source is dominant in the low energy band, while the later two are dominant in the high energy band.