Particle simulation of opening process in plasma opening switch by applying external quasi-axial magnetic field

In this paper, the opening process of plasma opening switch (POS) with different magnetic coil positions, placed inside the cathode or outside the anode, is investigated systematically by using particle-in-cell (PIC) simulation method, in order to study the operation characteristic of the coaxial POS with inner cathode in external quasi-axial magnetic field. The space-time change of electromagnetic field and the kinetic behavior of electrons in the plasma area of the POS had been simulated, and the opening process of the inner-cathode POS had been specially studied. The result indicates that when the coil is placed inside the cathode, the curvature and radial component of vector magnetic intensity in switching area are bigger and the radial component is smaller in the center, so the influence on opening process of this coil magnetic field is small. When the coil is placed outside the anode, the magnetic field in the switching area has good uniformity and the original distributing of the angular magnetic field is changed, so the movement trajectory of electrons in the POS switch area is changed. It is easier to achieve the opening of the POS, so the amplitude of opening voltage is higher and the current loss of the POS is smaller. The common role of the quasi-axial and self-angular magnetic field make electrons of the plasma expand to the downstream in cone-shaped helix form.