Thermal regimes of cooling copper targets with intensive local heating

Results are presented from an experimental study of the temperature regimes of water-cooled targets irradiated by an electron beam about $10$ mm in diameter. The heat flux incident on the target ranged up to $43$ MW/m$^2$. Cooling systems used for the target were based on Poroinvar and “waffle” finning. Target temperature estimates are made with an improvement or deterioration in heat-transfer in the boiling region under the beam.