Development of SiPM-Based X-Ray Counting Scanner for Human Inspection

Extremely low dose, fast human-screening systems constitute a vital instrument in a modern world under terrorist threats. Only X-ray scanners provide visualization of concealed items hidden under clothing or inside the body. However, existing systems are inadequate in many large-crowd scenarios (including public transport) because of restrictions on dose load per person. The main aim of this paper is to develop an alternative system that provides satisfactory control. X-ray counting with energy resolution is recognized as the most promising technique to achieve the maximum sensitivity of X-ray detection. Therefore, combining the high sensitivity of silicon photomultiplier (SiPM) to low-intensity light pulses with the high X-ray detection efficiency of modern fast inorganic scintillators, we are developing a prototype low-dose X-ray energy-resolved counting system for routine security purposes. Such an approach allows a reduction in the absorbed dose in a human body and can also improve the image quality for the typical doses currently used in the conventional X-ray systems. Moreover, a charge integration mode for high-intensity X-ray can extend the dynamic range of the system. In this paper, we present results obtained using a mature SiPM-based fast scintillation detector proof-of-concept prototype, incorporating an extremely low-dose X-ray scanner in counting mode, with energy discrimination.