Random pulse multichannel amplitude analyzer under high counting rate

Abstract

The invention discloses a random pulse multichannel amplitude analyzer under a high counting rate, and an FPGA single chip is used to complete main functions. In an FPGA, a digital detector pulse signal is differentiated, and a differential signal is used to generate a pulse start and stop signal which controls the pulse amplitude detection. When the pulse start and stop signal is invalid, the estimation of a baseline value of a detector pulse signal is started, the maximum value of the detector pulse signal is detected when the pulse start and stop signal is valid, and a corresponding amplitude value of a detector pulse is obtained by subtracting the currently estimated baseline value from the maximum value. A number of pulses of a corresponding differential signal is judged in a certain time after the detector pulse signal is valid, if the pulse number is larger than or equal to 2, detector pulse signal stacking is judged, and the pulses are not included in an energy spectrum.

Description

technical field [0001] The invention relates to a random pulse multi-channel amplitude analyzer at a high count rate, in particular to a digital multi-channel pulse amplitude analyzer for collecting the energy spectrum of an ɣ-ray detector signal. Background technique [0002] The multi-channel pulse amplitude analyzer plays an important role in the detection of radiation events, and can obtain ray energy spectrum data. In different applications, the range of the analyzer can be set to 1024 channels, 2048 channels, 4096 channels, etc., and each channel can be simultaneously Measurement. The output signal of the radiation detector is random, and the pulse signal is superimposed on the changing baseline. When multiple radiation events occur within the resolution time of the detector, the output signal of the detector will pile up. At high count rates, the pulsed The accumulation is more serious. With the development of radiation detection technology and the continuous improv...

AI Technical Summary

Problems solved by technology

Although this method can achieve a high counting pass rate, because the baseline of the detector pulse signal changes with the count rate, the threshold value changes relative to the baseline, and small-amplitude pulse loss and pulse start-stop signal jitter will occur. There are large errors in estimation and amplitude detection. When judging pulse accumulation, it is necessary to know the expression of the detector pulse signal, and the error in the actual expression fitting is also large.

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