Melting of copper by an intense and pulsed heat source

The one-dimensional Stefan problem of heat conduction is solved including evaporation cooling i.e. for conditions similar to those occurring in vacuum arcs, when the current constricts. For high values of heating power density a quasi-stationary state is found, i.e. when the melting depth does no longer increase despite further heating. The dependence of this maximum on the heating power density and duration is discussed for copper.