SIGNAL-TO-NOISE RATIO AT THE OUTPUT OF A FLAW DETECTOR WITH A MOSAIC SEMICONDUCTOR HARD X-RAY DETECTOR AND DIGITAL SIGNAL PROCESSING.

Expressions are derived for the signal, the background, and the noise at a silicon detector concerned with steel components and x-rays of maximum quantum energy 30 Mev. Estimates are made of the noise arising from fluctuations in the number of carriers multiplied in the detector and also of the generation-recombination and thermal noise. Expressions are given for the signal-to-noise ratio at the output of a flaw detector with digital data processing, which works with or without adaptation to the radiation flux. There is an advantage in a system that adapts to a static radiation flux. Relationships are given for this for the signal-to-noise ratio in relation to the quantization step for the correcting current, which enable one to relate the parameters of the digital system to those of the detector and to the monitoring sensitivity.