Thallium Bromide Devices for PRD and SPRD Applications

Thallium bromide (TlBr) is a wide bandgap compound semiconductor which has several advantages relative to the flagship compound semiconductor radiation detector material, CdZnTe. Until recently the suitability of TlBr for gamma-ray detection was challenged by its short room temperature lifetime. Currently, it has been shown that periodic switching of bias on TlBr detectors can result in room temperature device lifetimes exceeding 10,000 hours of continuous operation. An ANSI-compliant Personal Radiation Detector (PRD) prototype NuVu
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, which is based on bias-switching of planar TlBr devices meeting the required sensitivity and other performance criteria has been fabricated. This is the first demonstration of a handheld device using TlBr. The performance of large area TlBr planar detectors for use in spectroscopic (SPRD) applications is also shown. Also, an overview of the status of commercial off-the-shelf SPRDs based on scintillators and semiconductors is given, and the relative advantages of TlBr within this context is described.