Energy balance in the interaction of intense high-temperature plasma flows with solid targets

The energy balance in the interaction of intense (W≈7 MW/cm2, Q≈130 J/cm2) flows of a high-temperature (Te+Ti≈0.7 keV deuterium plasma with targets made of different materials (graphite, tungsten, copper, etc.) is studied experimentally. It is shown that radiation plays a decisive role in the interaction energy balance: a plasma layer arising near the surface of the eroded target reemits most of the plasma-flow energy into the surrounding space. No more than 50 J/cm2 reaches the surface. Then, this energy is expended primarily on the target heating and only a small fraction (less than 3 J/cm2) is spent on the evaporation of the target surface layer. It is shown that, for targets made of high-Z materials, the energy reaching the surface is transferred predominantly by radiation.