Research of the quantum noise characteristics of X-ray source

The characteristics of quantum noise in the low-dose X-ray imaging system were studied in the paper. Firstly several images were captured continuously in the ease of constant X-ray intensity, then the non-uniformity of these images were corrected respectively in order to eliminate the impact of system noise on the analysis of quantum noise, finally the fluctuation of image gray was studied to get the characteristics of quantum noise of the X-ray source. The experimental results show that X-ray quantum noise is of a characteristic with a zero mean and a variance related to light intensity. When intensity is increased, the quantum fluctuations reduce both in time and in space. Through the analysis of variances in different areas of images, we found that the closer the area is to the center of the X-ray source, the smaller quantum fluctuation is. (authors)