Simulation Of ?-? Particle Discrimination Based On Phoswich Detector

Phoswich detector is a kind of scintillation detector whose scintillation is assembled by different kind scintillation and which used one photomultiplier. According to different kind of scintillation have different interaction with different particles, this kind of scintillation detector is suitable for particle discrimination. This paper designed a plan of phoswich detector which could detect ?- particle and ? particle. In this plan, selection of scintillation material?photomultiplier and other parts and design of geometry size have been discussed. Then GATE, a kind of simulation software based on Geant4, have been used to simulate the geometry size?material?? radioactive source 214Bi?? radioactive source214 Po and Particle transport process, try to discriminate the pulse amplitude between ? particle and ? particle. Then the result shows that amplitude spectrum of ? particle and ? particle could be crossing. Some relevant research shows the discrimination effect may be better if we use pulse shape discrimination method. In the last chapter, Matlab has been used to simulate the pulse shape of scintillation detector of ? particle and? particle according to the statistical properties of nuclear signalwaveform, and compare three different kind of pulse shape discrimination method——charge comparison method ? risetime method and pulse gradient analysis and the result showed charge comparison method have best discrimination effect. Because 214 Bi and 214 Po are Radon daughters,this dicsrimination method have a significance of measuring Radon and artificial radioactive aerosol.