Structure Design of Heating Films with Magnetic Field Suppression for Atomic Sensors

Atomic sensors have inherent advantages in small size and high accuracy because their sensitive elements are atoms. To increase the strength of the output signal with such a small size, the temperature of the vapor cell is increased to get a higher polarized atomic density. However, the cell is usually heated by an electric heater, generating an additional magnetic field. Non-magnetic heating technology of the cell in atomic sensors is a crucial issue, especially the magnetic-sensitive one. This paper proposes a sixteen pole magnetic moment structure of coil used in the heating film for magnetic-sensitive atomic sensors. Firstly, based on the derivation of Biot-Savart law, the relationship between the magnetic field and the different types of the coil is established to achieve a smaller field. According to the relationship, the structure of different coils is designed for the suppressed magnetic field. Finally, an electromagnetic simulation is carried out to verify the effectiveness of the designed structure. The results show that the circular coils with a compensation line reduces the magnetic field at 2 mm height from 713 pT/mA to 539 pT/mA compared with the square coil with a compensation line.