Bias Conditioning of TlBr Arrays

Thallium bromide is a very promising semiconductor as an efficient, room temperature gamma ray detector material due to its high density, high atomic number, and wide band gap. Additionally, due to its relatively low melting point it has the potential to be lower cost than CZT. High electron mobility-lifetime products have enabled the fabrication of 10 mm thick TlBr arrays with energy resolution of about 2% FWHM at 662 keV without corrections for the interaction depth at room temperature. To reach optimum performance, TlBr detectors often require continuous bias for an initial "conditioning phase." In this paper, we report not only on the investigation of the initial conditioning phase with fresh arrays, but the second or subsequent conditioning phases. To probe the active volume during the conditioning phase, a collimated isotopic source will irradiate at various depths of 10 mm thick arrays.