ION BEAM INDUCED CHARGE COLLECTION (IBICC) STUDIES OF CADMIUM ZINC TELLURIDE (CZT) RADIATION DETECTORS1 B.L.Doyle, G.Vizkelethy2, and D. S.Walsh

Cadmium Zinc Telluride is an emerging material for room temperature radiation detectors. In order to optimize the performance of these detectors, it is important to determine how the electronic properties of CZT are related to the presence of impurities and defects , that are introduced during the crystal growth and detector fabrication. At the Sandia microbeam facility IBICC and Time Resolved IBICC (TRIBICC) were used to image electronic properties of various CZT detectors. Two-dimensional areal maps of charge collection efficiency were deduced from the measurements. In order to determine radiation damage to the detectors, we measured the deterioration of the IBICC signal as the fimction of dose. A model to explain quantitatively the pattern obsemed in the charge collection eftlciency maps of the damaged detectors has been developed and will be discussed in the paper.