Simulation on the Magnetic Shielding Structure of Ionization Gauge in a Superconducting Magnetic Field

In the superconducting magnetic field of a fusion device, the uncertainty of vacuum measurement increases because the ionization gauge cannot meet the needs of accurate measurement due to physical mechanisms such as filament deformation and changes in the trajectory of charged particles.Based on the basic principles of magnetic shielding, two semi-closed and open-type multilayer shielding structures were designed, and the simulation was carried out using Maxwell finite element software.The shielding effectiveness was obtained in different material layer thicknesses, different field directions, and other conditions.The results show that the shielding effectiveness increases with the increase of the radial thickness of the iron layer material.It is also found that the thickness of the superconducting material layer and the end thickness of the iron layer material have little effect on it.In the range of 0°-90°,the shielding effectiveness firstly decreases and then increases.The shielding effectiveness reaches the maximum value at 90°.This work provides a reference for the engineering design of the shielding structure of the ionization gauge under complex magnetic field application conditions.