HT_c SQUID工作环境低频磁干扰消除研究

Research on elimination of low frequency magnetic disturbance to HT_c SQUID

针对高温超导量子干涉器(HT_c SQUID)磁强计技术在非磁屏蔽环境中受到的极低频干扰,实验研究了主动补偿方法消除这种干扰的可行性和有效性。实验由高精度程控电流源提供电流,通过亥姆赫兹线圈产生用于抵消极低频干扰的补偿磁场,使用两套HT_c SQUID磁强计搭建了测试系统,其中一套用于低频磁干扰背景的探测,另一套用于磁干扰补偿消除效果的甄别。结果表明,这种动态补偿消除方法可以达到比较好的效果。

Aiming at the very low frequency disturbance of HT_c SQUID magnetometer technology in non-magnetic shielding environment, the feasibility and effectiveness of active compensation method to eliminate this disturbance were studied experimentally. The current in the experiment was supplied by a high precision programmable current source. A compensating magnetic field was generated by Helmholtz coil to resist negative low frequency disturbance. Two sets of HT_c SQUID magnetometers were used to build the test system. One was used to detect the background of low frequency magnetic disturbance, the other was used to discriminate the effect of magnetic disturbance compensation. The results show that this dynamic compensation elimination method can achieve good results.