用于高能中子监测的扩展型中子雷姆仪的设计

An Improved Neutron Rem Counter Design for High- energy Neutron Dose Monitoring

ABE-CYCIAE是一种基于标准AB雷姆仪的扩展型中子雷姆仪,该设备将用于HI-13串列加速器升级工程的中子在线监测。设备采用一根BF3管进行中子探测,使用聚乙烯及掺硼聚乙烯作为主要的慢化材料。通过使用MCNP软件对中子能量响应曲线进行模拟,计算的热中子到100 Me V的中子能量响应能较好的符合ICRP74号报告给出的注量剂量转换曲线。BF3管输出的脉冲信号经过电荷灵敏前置放大器放大,并由50 Hz陷波器除去工频干扰后,送入主放大器和计数器进行成型放大和计数。

An improved neutron rem- counter ABE- CYCIAE is based on the standard AB rem- counter which will applied in the online neutron dose monitor system of BRIF project. A BF3 proportional counter is used in the equipment. PE and Boron- doped polyethylene is used as the main material for the moderator. The neutron energy response of ABE- CYCIAE is calculated by MCNP. The neutron energy response of the thermal neutron to 100 Me V is well corresponds to the flux to dose conversion curve from ICRP- 74 report. The pulse signal of BF3 tube is amplified by charge sensitive pre- amplifier,power frequency interference is removed by 50 Hz wave- trap,and then sent to the main amplifier and counted by a scaler.