Effective Volume of TlBr Semiconductor Detector.

TlBr semiconductor detectors are candidate high-detection-efficiency, high-energyresolution, and room-temperature gamma-ray spectrometers. We evaluate the effective volume of a small-anode TlBr detector with a guard electrode through basic experiments and simulations, which are conducted for various voltages applied to the guard electrode. We confirm that the detection efficiency increases with decreasing guard voltage compared with the anode and saturates at a certain value. Under saturation conditions, the effective volume is evaluated to be 56% by simulation. In addition, we experimentally confirm that the energy resolution can be improved for a small-anode TlBr detector with a guard electrode by correcting the signal pulse height by pulse shape discrimination. [ABSTRACT FROM AUTHOR]