无自旋交换弛豫原子磁强计的主动磁补偿

由于外界磁场扰动会降低无自旋交换弛豫(SERF)原子磁强计的磁场测量灵敏度,本文根据SERF原子磁强计的测量原理,提出了一种基于原位磁测补偿外部磁场扰动的方法。该方法通过调制解调的方法对3个方向的磁场进行解耦,实现3个方向磁场信息的独立测量。然后,将3个方向磁场的测量信息作为反馈,调节电流源输出给线圈的电流,使线圈产生一个与外界扰动磁场大小相同方向相反的补偿磁场。最后,在现有的SERF原子磁强计实验平台上搭建了主动磁补偿系统,实现了对外部扰动磁场的补偿。与手动补偿方式相比,本文提出的主动磁补偿方法可将剩余磁场的平均值从0.317 8nT降低到0.040 4nT,同时将剩余磁场的均方差由0.348 1nT降低到0.024 7nT。得到的实验结果验证了本文所述方法的有效性。

Application of Optical Fiber in Radiation Detection Systems

In the last years, the production of optical fibers cables has made possible the development of a range of spectroscopic probes for in situ analysis performing beyond nondestructive tests, environmental monitoring, security investigation, application in radiotherapy for dose monitoring, verification and validation. In this work, a system using an optical fiber cable to electromagnetic signal transmission from a NaI（TI） radiation detector is presented. The innovative device takes advantage mainly of the optical fibers large passband, small signal attenuation and immunity to electromagnetic interference to application for radiation detection systems. The main aim was to simplify the detection system making it to reach areas where the conventional device cannot access due to its lack of mobility and external dimensions. Some tests with this innovative system are presented and the results stimulate the continuity of the researches.