Signals from guard rings on side wall of CZT detectors

Researches on CZT detectors emphasize on how to correct the incomplete charge collection due to the defects in CZT crystals and to improve the performance of CZT detectors. Normally to reduce the surface leakage current and to shape the weighted electric field the guard ring on side wall or on the anode surface surrounding the pixel is applied. Because the guard ring is on the side wall of CZT detectors and is sensitive to the transfer of induced electrons and holes, we expected that the signals from the guard ring could provide the charge transfer information. At first we simulated the electric field inside planar CZT detectors and pixel CZT detectors with single guard ring covering the whole side walls or double guard rings (one is close to the pixel surface and another one is close to the cathode surface). We also changed the electrode surface size and kept the thickness unchanged to compare the variation of the inside field. Preliminary results are provided here