High-speed continuous X-ray imaging method based on SiPM auto-encoding detector

High-speed X-ray imaging can be used to observe the internal evolution of objects in the microsecond range. However, obtaining data and processing images continuously are difficult when the speed of X-ray imaging is more than one million frames per second (fps). The novel method of high-speed X-ray imaging, which is based on a SiPM auto-encoding detector, was proposed. The different response to X-ray is realized by adjusting the bias voltage of different pixels to encode the analog signals. The analog signals from multiple SiPM pixels are simplified into a single signal. In this way, SiPM is constructed as the SiPM auto-encoding detector, which greatly reduces the amount of analog signals to be sampled for each frame of X-ray image, and then the image is reconstructed in the upper computer. The feasibility of the imaging method was verified by coupling the pixelated SiPM and lutetium-ytterbium scintillation crystals to construct a SiPM auto-encoding detector. Six patterns were exposed when pulsed X-rays were performed at frequencies of 100 and 500 kHz. Then, the number of image pixels was compressed from 16 to 4. The peak signal-to-noise ratio of the reconstructed images was above 41, and the structural similarity was above 0.99. Experimental results demonstrated that the speed of continuous X-ray imaging reached 500, 000 fps for six kinds of 4 x 4 pixel patterns. This method can be applied to improve the speed of high-speed continuous X-ray imaging.