High-flux experiments and simulations of pulse-mode 3D-position-sensitive CdZnTe pixelated detectors

In this work we present high-flux experiment and simulation results of 3D-position-sensitive CdZnTe pixelated detectors operated in pulse mode. Charge transport properties used in our simulations were carefully calculated through direct comparison between measured and simulated charge induced signals using two different methods: irradiating with α-particles on the lateral side surface of the detector at normal bias and irradiating with Mo-K_αX-rays (Molybdenum) on the cathode surface at reverse bias. Measured and simulated spectra as a function of increasing flux showed energies shifting towards lower energy bins followed by complete absence of spectral information, which was found to be caused by positive space charge build up distorting and completely breaking down the operating field as flux increased. More importantly, we developed a complete 3D framework that can be extended to other semiconductor detector technologies to study and predict their performance under high-flux scenarios.