Виявлення впливу способу магнітного екранування на топологію магнітного поля в прискорювальному каналі Холловського двигуна

This study investigates magnetic system in the ST-40-type Hall-effect thruster and its modification with magnetic shielding of the accelerating channel. The task addressed relates to the lack of systematic quantitative data on the influence of magnetic shielding techniques on the topology of the magnetic field in the channel. The associated parameters that affect the erosion of the walls and the stability of the engine operating modes remain undefined. This work reports mathematical modeling of the magnetic field topology for the engine of the classical scheme and two variants of magnetic shielding: with an external magnetic shield and using a magnetically soft hollow anode. Spatial distributions of the radial component of the field induction were determined and induction gradients along the axis of the accelerating channel were derived. It is shown that for the classical scheme the maximum induction gradient is about 0.67 T/m. The external magnetic shield increases it to 1.17 T/m, and the hollow anode – to 1.29 T/m, that is, 1.7–1.9 times. The results are explained by a change in magnetic resistance and redistribution of magnetic flux, which leads to deformation of the lines of force, their orientation along the dielectric walls of the channel, and removal of the maximum magnetic field induction beyond the engine section. A distinctive feature of this study is a direct quantitative comparison of the magnetic field topology for different design schemes on a single geometric and current basis, which made it possible to objectively assess the effectiveness of each variant of magnetic shielding. The implementation of results is possible in the design and optimization of magnetic systems of Hall engines of medium power class under conditions close to laboratory and ground tests. Their application could contribute to reducing erosion, increasing discharge stability, and increasing the resource