Low noise magnetic field compensation based on differential biplanar coils with small coil constant

• Published in: Measurement : journal of the International Measurement Confederation 2024-02, Vol.226, p.114115, Article 114115
• Main Authors: Li, Yanbin, Dou, Shuai, Liu, Xikai, Cui, Peiling, Yang, Zhouqiang, Li, Haitao, Wen, Tong
• Format: Article
• Language: English
• Subjects: Differential biplanar coils design; Differential evolution optimization; Low noise magnetic field compensation; Small coil constant
• ISSN: 0263-2241; 1873-412X
• DOI: 10.1016/j.measurement.2023.114115

Magnetic field noise is a key factor limiting the resolution of quantum precise measurement. In active magnetic field compensation systems, the large coil constant and fixed noise of the coil and current source, respectively, cause excessive noise. This study proposes a differential biplanar coils (DBCs) design method by comprehensively optimizing two sets of biplanar coils with differential evolution (DE) algorithm, which can reduce the coil constant by two magnitude orders while ensuring high uniformity. The peak-to-peak magnetic field at the center point is reduced to 0.8 pT, and the magnetic field noise is reduced to 8 fT/Hz, which is a reduction of 94.4%. The low noise active magnetic compensation system based on the differential biplanar coils can improve the accuracy of the magnetic shielding room (MSR) internal magnetic field control and reduce magnetic field noise effectively. The proposed method contributes to generating a near-zero magnetic field environment with low magnetic field noise, which is critical to promoting magnetoencephalography (MEG) measurements. •Comprehensive design and optimization method for biplane coils.•Low noise magnetic field compensation system.•Working environment for the precise MEG measurement.