Development of CZT strip detector modules for 0.05- to 1-MeV gamma-ray imaging and spectroscopy

Abstract

We report progress in our study of cadmium zinc telluride (CZT) strip detectors featuring orthogonal coplanar anode contacts. We specifically report on the performance, characterization and stability of 5 and 10 mm thick prototype CZT detectors fabricated using material from several manufacturers. Our ongoing work includes laboratory and simulation studies aimed at optimizing and developing compact, efficient, high performance detector modules for 0.05 to 1 MeV gamma radiation measurements with space-based instrumentation. The coplanar anode strip configuration retains many of the performance advantages of pixel detectors yet requires far fewer electronic channels to perform both 3-d imaging and spectroscopy. Minimizing the channel count is important for large balloon or space instruments including coded aperture telescopes (such as MARGIE or EXIST) and Compton imaging telescopes (such as TIGRE or ACT). We also present plans for developing compact, space qualified imaging modules designed for integration into closely packed large area detector arrays. We discuss issues associated with detector module and array electronics design and development.

Cadmium–Zinc–Telluride photon detector for epithermal neutron spectroscopy—pulse height response characterisation

“…The present experiment seems to suggest that an improvement can be expected by detecting higher energy g-rays, say above 150-200 keV; due to the contribution of Compton scattering events. This could be done using thicker CZT crystals, which have recently appeared on the market and have good detection efficiency up to 500 keV [32]. Alternatively a Germanium detector could be used, which however has the disadvantage of being sensitive to the radiation damage by fast neutrons [29].…”

Continued Studies of Single-Sided Charge-Sharing CZT Strip Detectors

“…Polarities and shaping times are the same for both row and column channels. Also, the large area covered by the grid electrode should result in better depth resolution than was available from the individual strip column electrodes in our earlier single-sided strip detector design [2].…”

The Advanced Compton Telescope

“…Toward this end, however, we have studied competing technologies that could either augment or supplant those chosen for the baseline design. These include thin Si [29,19], liquid Xe (LXe) [2][3][4], CdZnTe [37,25,30], LaBr scintillator [39], and gaseous Xe (GXe) detectors [6,12,13]. Each of these detectors possesses capabilities that could potentially improve the performance over the baseline instrument-in terms of electron tracking (thin Si, GXe), fast timing (LXe, LaBr, GXe), or room-temperature operation (CdZnTe, LaBr).…”