THALLIUM BROMIDE SEMICONDUCTOR X-RAY AND GAMMA-RAY DETECTORS

Over the last few years, thallium bromide (TlBr) has been investigated for use as a semiconductor radiation detection material. This article reviews the history of TlBr detector development and describes the fabrication of state-of-the-art TlBr gamma-ray detectors. Studies of TlBr detectors of different chemical purity indicate that their performance is no longer limited by chemical purity, as was true previously. This is a result of our purification methods, which employ multipass zone-refining. We also report on the performance of vacuum-deposited (by sublimation, = 100 mu m thick) TlBr films as single photon detectors. They have surprisingly high mu tau for sublimed films, and X-ray detectors made from these films may find use in some X-ray imaging applications, including xeroradiography.