Optimization Research Of Digital N-? Discrimination Technology In The New Plastic Scintillator Detector EJ299-33A

The new type of plastic scintillator,EJ299,has allready been uesd for the detection of fast neutrons coming from nuclear materials.However,its n-gamma discrimination capabilities was inferior to that of liquid scintillator of the same size.This paper presents the optimization research on the n-? discrimination for novel plastic scintillator EJ299-33 A detector.The main work is as follows:.Firstly,based on the digital pulses acquisition and processing technology,the optimization research on the n-? discrimination for novel plastic scintillator detector by charge comparison method was presented.The influences of integral long gates and short gates?equivalent electron energy thresholds andhorizontal and vertical sampling precision of digitizers on the figure of merit(FoM)parameters were investigated,also the ratios of the tail integration to the long gate integration for neutron and gamma rays were calculated with fitting functions of average pulses.The results showed that the optimized integral short gate range is 30-50 ns as well as 450 ns for the long gate;and the PSD capabilities of DT5730 B are better than DT5751 with a threshold range of 100 keVee ?500keVee.Secondly,for the same group of digital pulses,the optimization research on the n-? discrimination using simplified charge comparison method and decay time method was also presented.For the decay time method,the influences of upper and lower thresholds?equivalent electron energy thresholds and horizontal and vertical sampling precision of digitizers on FoM values were investigated.On the other hand,for the simplified charge comparison method,however,the influences of integral long gates and short gates?equivalent electron energy thresholds and horizontal and vertical sampling precision of digitizers were investigated.Finally,based on the frequency domain singals analyzing technology,the optimization research on the simplifieddigital charge collection method was also presented.The influences of the integral beginning and end of D discrimination parameter?equivalent electron energy thresholds andhorizontal and vertical sampling precision of digitizers on the FoM parameters were investigated.The results showed that the optimized integral range for the D values is 90-500 ns;and the FoM values is greater than 1 for 300 keVee threshold;and the PSD capabilities of SDCC method are better than that ofDCC methodwhen the energy threshold is greater than250 keVee.