Laboratory coded aperture imaging experiments: radial hole coded masks and depth-sensitive CZT detectors

摘要

The proposed black-hole finder mission EXIST will consist of multiplewide-field hard X-ray coded-aperture telescopes. The high science goals set forthe mission require innovations in telescope design. In particular, wide energyband coverage and fine angular resolution require relatively thick coded masksand thick detectors compared to their pixel size, which may introduce maskself-collimation and depth-induced image blurring with conventional designapproaches. Previously we proposed relatively simple solutions to thesepotential problems: radial hole for mask selfcollimation and cathode depthsensing detector for image blurring. We have now performed laboratoryexperiments to explore the potential of these two techniques. The experimentalresults show that the radial hole mask greatly alleviates mask self-collimationand a ~1 mm resolution depth-sensitive detector scheme can be relatively easilyachieved for the large scale required for EXIST.