Flight x-ray CCD selection for the AXAF CCD Imaging Spectrometer

摘要

As part of our program to select and calibrate flight- quality, x-ray CCD detectors for the AXAF CCD imaging spectrometer, we have developed efficient detector screening methods. Our screening protocol, which measures device-level performance parameters (including noise, dark current and charge transfer efficiency) as well as x-ray spectral resolution in the 0.3 - 6 keV band, allows us quickly to identify which of the greater than 30 flight candidate detectors warrant the expenditure of severely limited time available for calibration. The performance criteria used to rank devices are discussed, and the details of the measurement methods are presented. Summary results of the screening measurements are presented for a large sample of devices, and detailed data on selected devices are described. We find that the performance variations among the sample of flight devices to be relatively small but significant.