相对永久密封真空康普顿探测器伽马灵敏度研究

Gamma Sensitivities of Compton Detector with Relatively Permanent Vacuum Atmosphere

针对强流脉冲γ射线探测，研制了厚入射窗结构真空康普顿探测器，并在^60Co辐照装置上，准直孔径为40mm的条件下，对2套样品探测器灵敏度进行了测量，得到了1．25MeV的了射线灵敏度，实验值分别为4．65×10^-22C/MeV和4．59×10^-22C／MeV．该实验值与蒙特卡罗程序MCNP的计算值（4．70×10^-22C／MeV）相比，误差范围一致，在0．5～3．0MeV能量区间，探测灵敏度的能量响应变化小于20％．实验证明：该探测器比薄窗结构真空康普顿探测器的灵敏度提高了60％，克服了薄窗探测器封装加工和静态真空保持的困难；保存使用期可达2年以上，达到了相对永久密封的目的，可应用于粒子注量率为10^20cm^-2·s^-1以上的强流脉冲γ射线测量．

A newly designed vacuum Compton diode detector with a thick incident window was developed and experiment was conducted to measure the sensitivity of the two present detectors in this study. For 1.25 MeV Gamma ray and a collimating diameter of 40 mm, the absolute sensitivity measured was 4.65 ×10^-22 C/MeV and 4.59×10^-22C/MeV, respectively, while the sensitivity calculated was 4.70×10^-22 C/MeV using the MCNP code. In the energy range of 0. 5- 3.0 MeV, the variation of sensitivity was less than 20%. The sensitivity of the detector was about 60% higher than that of the vacuum Compton detector with a thin incident window.Our results indicate that the performance of the present detector will be steady in two years and it can be used in the detection of intense pulsed gamma with fluence of 10^20cm^-2·s^-1.