A two-dimensional nonstationary model of the initiation of an explosive center beneath the plasma of a vacuum arc cathode spot

A numerical two-dimensional nonstationary model is developed to study initiation of the new explosive center beneath the plasma of a vacuum arc cathode spot. The process of heating a cathode surface microprotrusion was simulated numerically. The obtained results show that taking into account the ion impact heating and electric field of the space charge zone near the cathode surface ensured the "triggering" heat flux power necessary for developing the Joule heating of the microprotrusion followed by an explosion at reasonable values of the ion current and geometric parameters of the microprotrusion.