研究了对BC501A液体闪烁体对γ射线的光输出响应特性。实验上利用γ放射源(60Co,137Cs)测量了不同光电倍增管高压下,尺寸为Φ5.08 cm×5.08 cm的BC501A液体闪烁体探测器的脉冲幅度谱。利用Geant4软件进行模拟,计算结果与实验数据很好地符合,得到了能量分辨函数及能量刻度曲线。利用Geant4研究了BC501A的脉冲幅度谱的康普顿边缘Ec、康普顿峰Emax及康普顿半高点E1/2与能量分辨率的关系。同时模拟结果显示,随γ射线能量(0.2~3 Me V)的增加,康普顿边缘位置Nc/Nmax从0.8至0.7线性减少。
The light output response of BC501A liquid scintillator to γ-rays has been studied. The pulse-height spectra of BC501A (Φ5.08 cm × 5.08 cm) for different PMT high voltages have been measured using 137Cs, 60Co γ-ray sources. The Geant4 simulated pulse-height spectra showed a good agreement with experimental data. The energy resolution functions and energy calibration curves have been obtained by comparing measured light output distribution with simulated one. The position of the Compton edge relative to the position of the maximum and the half height of the spectra has also been studied using Geant4 in detail. The value of Nc/Nmax at the position of Compton edge decreases from 0.8 to 0.7 with the increase of incident γ-rays energy (0.2~3 MeV).