CdZnTe high-energy radiography detector

High-energy X-ray photons are generated by linear accelerators or flash X-ray sources. These pulsed sources produce a high number of photons in a very short time (from a few picoseconds to a few microseconds). CdZnTe detectors are well suited to detect such photons because of their high density and good sensitivity. The possible dynamic range can be very high (from 1 to more than 10 000 photons per pulse). Because of the short X-ray pulse duration, and the transport properties of the semiconductor, photon counting mode operation is not adopted. The only possibility is to integrate the charge provided by all the photons. In this paper, we will first present the behaviour of different HPBM CZT and THM CdTe:Cl single detectors under high-energy X-rays exposure. Then the performances such as dynamic range, linearity, signal-to-noise ratio and spatial resolution of a 2D detector prototype are presented. This detector is devoted to 60 ns flash radiography at several MeV. It is made by piling up 16×20×1 mm striped plates. Finally, the detector has 64×32 pixels of 1×1 mm2 surface and 40 mm in depth. xt step will be a 16×16×4×cm3 detector for high-energy flash radiography.