Improved Multipole Moment Electrical Heater for Magnetic Field Self-Suppression Based on Discrete Currents

The atomic vapor cell is an important part of the atomic sensor. These cells usually need to be heated to a high temperature to increase the density of alkali-metal atoms, and electrical heaters are typically used for this purpose. Atomic magnetometer is very sensitive to the magnetic field, resulting in a higher demand for nonmagnetic electrical heating technology. This study proposes an improved multipole moment electrical heater configuration for magnetic field self-suppression based on discrete currents. Compared to the previous
$2^{N}$
multipole moment configuration, this method not only considers the influence of the relative current direction, but also optimizes the current magnitude. First, a magnetic field analysis model of
$2^{N}$
multipole moment configuration was established, and a method of introducing the discrete current was proposed to improve the self-suppression effect of the magnetic field. Then, the genetic algorithm is used to optimize the current magnitude parameters and structural dimensions to design an improved multipole moment configuration to improve the self-suppression effect. Finally, the effectiveness of this method is verified using finite element simulations. Compared with the previously developed
$2^{N}$
multipole moment configuration, the proposed heating configuration generates a magnetic field of 0.79 nT at the cell center point and an average magnetic field of 1.15 nT within the central region of the cell under the same heating power, thereby reducing the average magnetic field by approximately 33%.