Scaling of Magnetic Circuit for Magnetically Shielded Hall Effect Thrusters

Abstract

Magnetic shielding (MS) is a well-assessed technique adopted in Hall effect thrusters (HETs) to minimize the channel wall erosion mainly due to high-energy ions bombardment, thus improving HETs operating life. The magnetic topology of a MS-HET depends on the magnetic circuit elements’ shape, dimension, and relative offsets, together with magnetic coils. The design of a MS configuration typically involves an iterative “trial and error” approach, requiring high time costs to perform several numerical computations with finite element methods to get the final magnetic circuit topology. To speed up the design procedure of MS-HETs, a simple methodology was developed focusing on thrusters with power levels lower than 5 kW. It relies on the use of a database of MS-HETs (power range 0.1–5 kW) built by scaling a known MS thruster. As application, the magnetic circuit for a 2000 W MS-HET has been designed. A simulation of plasma within the accelerating channel and near plume region, by means of a Hybrid code, has assessed that effectively the new thruster was magnetically shielded.