An Analytical and Experimental Study of Post-Arc Phenomena in Vacuum

The post-arc behavior of rapidly commutated (1.2 kA/¿s) diffuse vacuum arcs has been studied both experimentally and analytically. Three interrupters were tested in a synthetic test circuit which allowed independent variation of current prior to commutation and dI/dt at, and dV/dt following, current zero. The interrupters differed in contact material, effective contact area, and contact spacing. An analytical model for sheath growth has been developed which takes into account current variations during the ion flight time. The model predictions agree well with experimental results.