3D position sensing on UltraPeRL CdZnTe detectors

Experimental results of depth and lateral position sensing on UltraPeRL pixellated CdZnTe detectors using signal ratios are presented. Each detector employs one CdZnTe crystal of 20 mm times 20 mm times 5 mm with 8 times 8 pixel electrodes fabricated on the anode surface. The anode pixel pitch is 2.4 mm. The signal ratios are calculated using the signals induced on the collecting pixel and the eight neighboring pixels. The signal on each collecting pixel is then corrected for depth of interaction using the signal ratios. We obtained 7.6%, 4.2% and 2.5% FWHM energy resolution at 122 keV, 356 keV and 662 keV, respectively.