Preparation of High-Sensitivity Cadmium Sulfide Cells for Gamma-Ray Detection

Single synthetic CdS crystals 3×4×10 mm, having dark conductivities from 10−9 to 10−10 ohm−1 cm−1, were prepared for gamma-ray detection. In a 50 r/hr Co60 field the conductivity increased to 10−6 ohm−1 cm−1. The crystals were grown in a static system at 930±5°C. Indium electrodes were applied by an ultrasonic soldering technique. The effect of constant excitation from radium to reduce the crystal rise time is illustrated. The time response and spectrographic analysis of crystals and commercial CdS powders is presented.