Possible mechanisms for electric-field-free gas breakdown

It was reported in the late 1960s [1] that gas breakdown occurs during explosive and electrical operation of magnetic flux compressor generators (FCGs). Recently [2,3], we reported on experimental evidence of the formation of plasma and its propagation in the gas within the FCG with no electric field in the system. We named this phenomenon electric-field-free gas breakdown. In this paper, we discuss possible mechanisms for this type of gas breakdown. The first mechanism is related to the ionization of the gas by a sequence of shock processes caused by an explosively expanding metallic armature within an FCG. The second mechanism is related to the ejection of high-speed particles from the explosively shocked metallic surface of an FCG armature.