屏蔽环境下残余磁场三轴分量原位高精度测量与补偿方法研究

The effect of SERF (Spin Exchange Relaxation Free) provides fT-level sensitivity in magnetic field measurement, which has landmark significance. There are wide prospects for SERF magnetic measurement device. However, a high temperature is needed to realize SERF regime, which becomes one of the essential issues that limit the applications at present. This proposal aims to achieve the SERF regime in a low temperature by fully compensating the residual field under shielding environment. Firstly, through analyzing the characteristics of the electron spin resonance under the synergistic effect of the residual and applied fields, the in-situ measurement method of the residual field based on the sensitive head of the SERF magnetic measurement device is presented. Subsequently, by adopting the strategy of "magnetic field cancellation", the precise compensation models of the residual triaxial components with in-situ characteristic are established. Finally, based on the SERF magnetic measurement device, the verified experiments using for measuring and compensating the residual field under shielding environment are demonstrated. Anticipated results of this proposal can provide essentials for achieving the SERF regime at a low temperature, simultaneously, it plays a positive role in expanding applications of the SERF magnetic measurement device.

基于原子无自旋交换弛豫（Spin Exchange Relaxation Free，SERF）效应的磁场测量敲开了fT量级超高灵敏磁场探测的大门，具有里程碑式的意义，基于该效应的磁场测量装置具有广阔应用前景。然而，目前实现SERF态仍需较高温度，是限制该装置应用范围的关键问题之一。本项目拟采用充分补偿屏蔽后残余磁场方案实现低温SERF态目的。首先，剖析残余磁场与应用磁场协同作用下的电子自旋共振特性，结合电子顺磁共振理论，基于SERF磁场测量装置敏感表头开展残余磁场三轴分量原位测量方法研究；其次，采取“磁场抵消”策略，建立残余磁场三轴分量高精度实时补偿模型，研究残余磁场三轴分量高精度实时补偿方法；最后，基于SERF磁场测量装置展开屏蔽环境下残余磁场三轴分量原位高精度测量与补偿联合实验研究。本项目预期研究成果可为实现低温SERF态提供必要的研究储备，同时对扩展装置应用范围具有积极促进作用。

随着量子调控机理与光电检测技术的发展与突破，基于原子无自旋交换弛豫（Spin Exchange Relaxation Free, SERF）效应的磁场测量敲开了fT量级超高灵敏磁场探测的大门，具有里程碑式的意义。基于该效应的磁场测量装置具有广阔的应用前景，然而，目前实现原子SERF态仍需较高的工作温度，这成为限制该装置应用范围的关键问题之一。实现原子SERF态需两大关键因素之一是敏感表头所处位置的环境磁场强度，其一方面有助于在较低工作温度下实现原子SERF态，降低装置整体功耗、扩展SERF磁场测量装置应用范围；另一方面，有利于抑制由磁场和温度波动造成的装置稳定性问题，具有重要的理论意义和应用价值。本项目分别利用电子顺磁共振原理和超极化21Ne在外磁场下的自由自旋进动特性，实现了屏蔽环境下的残余磁场三轴分量原位测量；同时，基于磁场抵消思路，利用Labview实现了残余磁场三轴分量的高精度补偿，此外，为了提升磁场测量和补偿精度，还研究了磁场与激光方位对准方法。本项目顺利完成，研究成果可为实现低温SERF态提供必要的研究储备，同时对扩展装置应用范围具有积极促进作用。在本项目的支持下，共发表高水平SCI论文（IF>5）2篇，授权国家发明专利1项，培养硕士研究生2人。