Influence of Residual Transverse Magnetic Field on Sheath Expansion Process in Vacuum Interruption

The objective of this paper is to quantitatively determine the influence of the residual transverse magnetic field (TMF) on sheath expansion process after current interruption in vacuum. A two-dimensional (2D) particle-in-cell (PIC) model was adopted. The investigated residual TMF ranged from 0 to 300 mT. The simulation results showed that except an ion sheath existing in the sheath expansion period, there appeared an electron sheath, which is formed under the influence of the TMF. Moreover, when there is no residual TMF, the voltage drop mainly applied on the ion sheath. With the application of residual TMF, the voltage drop mainly applied on the electron sheath. Finally, residual TMF has a remarkable blows effect on the electrons. Few electrons diffused to the area between anode and shield under the influence of the residual TMF.