Optimal Design for Electric Heating Coil in Atomic Sensors

This article proposes a novel approach to optimize the heating coil of atomic sensors, which can reduce the impact of the heating process on performance. The atomic sensors utilize vapor cells to measure physical quantities by monitoring the precession state of alkali metal atoms, which are influenced by the magnetic field. Achieving a sufficient signal strength requires a high temperature to achieve the desired alkali metal atom density. However, the commonly used electric heating method introduces magnetic interference from the heating current. Therefore, this article proposes an optimal design scheme in 3-D space to mitigate the magnetic field generated by the heating coil in the atomic sensors. By designing vertical and planar structures, the influence of the magnetic field generated during the heating process on alkali metal atoms can be significantly decreased. First, the number of layers in the vertical structure is designed, and a three-layer optimal solution is proposed. Second, the planar structure optimization is designed by using the sparrow search algorithm (SSA) to generate a minimum spatial magnetic field by the heating coil with the same length. The simulation results show that the proposed design coil reduces the magnetic field from 803.44 to 160.72 pT/mA at a distance of 2 mm from the coil, a significant improvement over the $2^{N}$ configuration. Experimental results confirm that the magnetic field generated by the three-layer vertical structure is smaller than that of other multilayer structures, and the magnetic field generated by the optimized coil is smaller than $2^{N}$ coil.