Abstract:

A nuclear material level measurement system is introduced,which is based on the long plastic scintillator.According to the principle that the intensity of the rays attenuate after passing through substance,the height of the substance is determined by the change of the ray intensity.The hardware structure of the scintillation detector is analyzed.Both ends of the plastic scintillator counts decaying exponentially are summed.The both ends of long plastic scintillator with photomultiplier tube are used in the scintillation detector.The emitter follower and hysteresis comparator circuit increase the detection signal on load capacity,filter noise and discriminate signal.Relationship between the two ends signal of the detector and the relative position of the point-like radiation sources is established after the performance test results of HND-S2 plastic scintillator.According to the integration operation,the ideal model of the actual field of linear sources is determined,which is used to measure the height of the material level.The system has high measurement accuracy with an error of less than 1% and can be widely used in petroleum,chemical,pharmaceutical and other industries.

Key words: level measurement;plastic scintillator;scintillation detector;radiation sources