| Popis: |
The theoretical research of the energy exchange process between metal macroparticle and nonequilibrium vacuum arc plasma is carried out. Researched range of plasma parameters was n=(10/sup 15-/10/sup 19/) cm/sup -3/ and T/sub e/=(1-5) eV, the model macroparticles had radius R=(1-10) /spl mu/m and velocities V=(1-100) m/s. In the theoretical model the processes of electronic emission and atom evaporations were considered. It is shown, that in the certain range of plasma parameters two different modes of maintenance quasistationary temperature of a drop can be realised. In one mode the energy flow from plasma on a drop is balanced by thermionic emission cooling, in another mode by the intensive evaporation of a drop material. The stationary temperatures of tungsten, gallium, copper and graphite particles were estimated. Temperature histories of a drop during its flight through the nonuniform cathode flash plasma are researched The slow drops are capable to get high enough temperature, and consequently can considerably decrease their size because of evaporation. |
