液闪探测器中子光响应函数刻度研究

Research on the Calibration of Neutron Response Function of Liquid Scintillator

BC501A液体闪烁体在临近空间高能中子测量中具有重要的应用价值,其光响应和能量分辨率对测量结果影响较大。对中子与BC501A液体闪烁体作用产生的反冲质子的光响应函数以及液闪的能量分辨函数进行了研究。利用5SDH-2串列加速器通过核反应获得单能脉冲中子源,实验获得单能中子的脉冲幅度谱,应用GEANT4等MC软件对实验进行模拟计算得到光响应谱,并与脉冲幅度谱进行拟合得到各能点中子的光输出以及其对应的能量分辨率,应用最小二乘法对中子光响应函数以及能量分辨函数进行了计算,并将计算结果与推荐光响应函数进行了对比分析。结果显示:模拟计算反冲质子能谱与单能中子脉冲幅度谱在末端边沿处拟合效果较好,中子光响应函数与其他文献中的研究结果基本一致。

To measure the radiation environment of near space, the response function of recoil proton come from the nuclear reaction between neutron and BC501A liquid scintillator has been researched. Pulse height spectrums are acquired by quasi mono- energetic neutron experiments. At the same time, light response spectrums of monochrome neutrons are obtained through MC software simulation. A series of neutron energy response and resolution of the detector are calculated by fitting the simulated neutron response spectrum to the corresponding pulse height spectrum. The neutron response function and the energy resolution function are solved through least squares method, and then the results are analyzed comparing with the reference neutron response function. The results show that simulated spectrums of recoil proton are fitting well with the pulse height spectrums of monochromatic neutron in the edge, and the calculated neutron response function are agree well with other relative researches.