强辐射场所无线γ测量装置

A Wireless Equipment for High γ-Dose Rate Monitoring

在强辐射水平的工作场所,广泛采用手持长杆式仪表接近目标测量其γ辐射水平,会造成测量人员受到较大剂量的职业照射。为此设计专用测量装置,采用无线传输方式,包含探测器、转发器和读出仪等。测量时,通过吊具、机器人等工具将探测器送至测点,测量人员在安全位置通过读出仪读数。由于中间无线转发器的引入,装置可以在无线电通讯环境极其恶劣的屏蔽场合实现正常通讯。探测器采用电离室,量程上限100 Gy/h,质量小于900 g,其平整、光滑的全密封结构利于减少沾污,并方便进行擦拭、冲洗去污;探测器掉入屏蔽水池会浮在水面便于处理,而不会沉入水底造成事故。为解决探测器内部的电子器件在强辐射场下寿命缩短的问题,将该部分设计成一个便于更换的模块,作为一种耗材由用户更换,并且在硬件和软件上采取措施确保在更换后不需再次刻度即可维持效率系数不变。通过内部计数器实现模块寿命预警,提醒用户提前更换,以防止在测量现场突然失效。装置在高通量工程试验堆热室检修等辐射作业监测中的应用获得成功。对于强辐射目标或场所测量,该装置辐射防护意义显著。

For the monitoring of high γ- dose rate, the handheld device is widely used, thus causes high personnel radiation exposures. For the above reasons, a special wireless equipment is designed. It is composed of a detector, a transmitter and a reading device. During measurement, the detector is delivered to the target area by tools. The operator can record the readings in a safe area. The equipment can communicate normally in very bad shielded wireless communication environments, thanks to the wireless transmitter. The detector is an ioniza- tion chamber with the upper measurement range of 100Gy/h. The weight of the detector is less than 900g. The smooth surface and omni seal structure design can reduce the opportunity of being contaminated. Even if the detector falls under disastrous conditions, it can float on shielding pond, without causing accident. To solve the problem of inner electronics working life being reduced under strong radiation damage, the electronics part is moduledesigned. There is a spare part, appropriate for replacing by the user. Hardware and software measures are applied to ensure that the efficiency factor will not change after replacing the electronics module and no reealibrating is needed. An inner counter will record the remaining module working life, alarming the user to replace at the proper time. The apparatus is successfully used in the hot ceil of HFETR. The equipment has great potentials in radiation protection for measurement of high γ - dose rate targets.