Position Sensing in CdZnTe Semiconductor Detectors via Proximity Charge Sensing Pixels

摘要

Proximity charge sensing is a novel technique used in the field of radiation detection. This research examines the simulationof a pixelated anode proximity charge-sensing device on CZT semiconductors to evaluate the potential performance of theproximity sensing technique on room-temperature detector materials for imaging purposes. The weighting potentials (WPs),of proximity-sensing and directly deposited electrode pixelated designs, were generated using ANSYS Maxwell, and thebest design will be considered for the implementation step in the future. The simulation investigated two features of theproximity design, pixel size and pixel pitch. Three different pixel sizes were used in the simulation designs, 0.5 × 0.5 mm~2,1.0 × 1.0 mm~2, and 2.0 × 2.0 mm~2. The 0.5 × 0.5 mm~2 pixel size had the best WP profile, where the generated signal for oneradiation energy did not depend on the interaction location. Pixel pitch was examined using the same pixel size, 1.0 × 1.0 mm~2,and varying the pixel pitch from 2.0 mm, 3.0 mm up to 4.0 mm. The results showed that as the pixel pitch increases, thesignal crosstalk (charge sharing between pixels) decreases. However, as the pixel pitch increases, the spatial resolution ofthe imaging system decreases, making it difficult to observe objects smaller in diameter than the pixel pitch. Additionally,proximity charge sensing designs showed better performance in terms of signal crosstalk for the same pixel size and pixelpitch in comparison with directly deposited designs.