This separation is equivalent to 0.5 arc seconds at the focal plane of the AXAF mirror assembly. The detectors are surrounded by a five-sided plastic scintillator anticoincidence shield in order to reject high energy charged particle induced events within the MCPs. This shield will also serve as a radiation monitor for the spacecraft to warn of the presence of a high intensity charged particle flux. 6 shows a schematic view of the HRC assembly. The total weight of the HRC is slightly under 250 lbs.
Dimensions are in inches.
A calibration wheel containing three radioactive sources is mounted on the instrument door. The total weight is 250 lbs. The HRC's parameters are summarized in Table 1.