Plastic scintillator is usually used to detect neutrons in high power pulsed neutron/gamma mixed radiation field. Since gamma rays can make background signals in the scintillator, it needs to take some measures to increase neutron/gamma discrimination. Based on the fact that electrons are much more easily deflected than protons in magnetic field, this text proposes a new method of increasing neutron/gamma discrimination of plastic scintillator. The Geant4 simulation indicates that the new method can be used to measure neutrons in fission mixed radiation field where, in some cases, gamma flux might be as high as two orders of magnitude of neutron flux.%在强脉冲束中子、γ混合辐射场中,一般使用塑料闪烁体探测器测量中子注量,为了尽可能地减少γ辐射的干扰,需要提高塑料闪烁体的n/γ甄别能力.利用电子与质子在磁场中的偏转半径不同,提出一种提高塑料闪烁体n/γ甄别能力的新途径,并采用Geant4输运程序探讨了该探测方法的可行性,模拟结果表明:该方法使用较薄的闪烁体和磁铁构成探测系统,可用于探测γ注量高于中子注量1～2个量级的强γ裂变辐射场中子.
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