A design method of a cylindrical radial uniform magnetic field coil

Abstract

The invention discloses a design method of a cylindrical radial uniform magnetic field coil, which comprises the following steps of: firstly, equally dividing the surface of the coil along the axial direction according to the azimuth angle of a cylindrical coordinate system, determining the surface current density expression on one side, and determining that the current density distribution on theother side is completely the same as that on the other side but opposite in current direction; secondly, deducing a magnetic field expression of a target field point, selecting the curvature of the current density as a penalty function of a constraint coil, setting a constraint factor of the penalty function, and solving a value of an undetermined coefficient in the current density expression byutilizing a regularization method to obtain a current density distribution condition of the cylindrical surface; and finally, obtaining an actual current routing shape of the cylindrical radial uniform magnetic field coil by using a flow function. The method serves as an inverse method of coil design, the size of the cylindrical coil is limited in advance, the coordinate position of a target fieldpoint is selected, then actual current distribution of the coil is obtained through calculation, the length-diameter ratio of the cylindrical coil is effectively controlled, and a gap can be reservedin the center of the coil to form a light through hole.

Description

technical field [0001] The invention belongs to the technical field of atomic magnetometers, and in particular relates to a design method of a cylindrical radial uniform magnetic field coil. Background technique [0002] With the advancement of science and technology, atomic magnetometer technology has been greatly developed in recent years, from optically pumped magnetometers and nuclear magnetic resonance magnetometers based on the principle of magnetic resonance to superconducting quantum interference magnetometers based on the Josephson effect. The development process of atomic magnetometer based on spin-free exchange effect (SERF) from strong meter (SQUID). The SERF atomic magnetometer uses the atomic spin effect to measure the magnetic field, and its magnetic field limit measurement sensitivity is better than that of the SQUID. It is considered to be a type of magnetometer with the most potential for extremely weak magnetic detection. [0003] The SERF atomic magnetom...

AI Technical Summary

Problems solved by technology

Among them, the three-dimensional magnetic field coil is used to generate a uniform spatial magnetic field. It is not only an actuator for actively compensating the magnetic field, but also a device for generating magnetic field excitation signals. Its structure limits the miniaturization of the SERF atomic magnetometer. At the same time, its magnetic field is uniform degree affects the relaxation rate of the atomic source

Usually, in SERF atomic magnetometers, saddle-shaped coils are mostly used to generate radially uniform magnetic fields. However, when the saddle-shaped coils generate uniform magnetic field performance is optimal, the ratio of its length to diameter reaches 1.75, and the redundant volume is too much

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