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The Influence of Magnetic Shielding on the Magnetic Field Structure of Penning Ion Source

The role of magnetic shielding is to protect the electromagnetic field of the source device from external interference and interference with nearby components or electronic circuits1. In this paper, using the Scalar Magnetic Potential finite-difference Method (SMPM)2, two different types of magnets (high permeability soft iron material and samarium-cobalt permanent magnet) magnetic fields are simulated and applied to the Penning ion source3, The results show that the addition of magnetic shielding makes a huge change in the magnetic field structure of some areas within the source, which is reflected in the decrease of the magnetic field in the local area and the sudden change of the magnetic field direction. At the same time, changes in the magnetic field structure will cause changes in the dynamic characteristics of the electrons in the source. We calculated the radial density of electrons in the Penning source, and the results showed that the addition of magnetic shielding is beneficial to reduce the fluctuation of electron density, thereby improving the uniformity of electron spatial distribution. The study of magnetic shielding is conducive to understanding the dynamic behavior of electrons and provides a reference for improving the source performance in the future.