Contact transition in metal armatures [railguns]

Metal armature contacts often transition from a low-voltage (⩽1 V) to a high-voltage (<51 V) state. The high-voltage state is characterized by arcing and considerable rail damage. It is desirable to delay or prevent the transition. Reliable prevention of transition has proven difficult because no validated physical model of the transition has been demonstrated. It is shown that armature contacts are adiabatic and that transition can be accurately predicted from basic physical principles