Droplet size distribution in a metal evaporated by high-current electron beam

The ablation of substance from an irradiated target as a result of liquid-vapor phase transitions is considered. Kinetic equations that describe the formation and growth of vapor bubbles in a melted metal are derived. The composition of products formed during ablation of a copper target under the action of a high-current electron beam has been studied. The droplet size distribution in the condensed phase has been determined, which can be used in solving the problem of nanopowder condensation. It is established that the dimensions of droplets in the ablated substance are determined by the kinetics of the evaporation process, rather than by the initial structure of the target material, and depend on the beam energy deposition rate. In the electron irradiation regimes studied, the droplet dimensions fall in the interval from several dozen to several hundred nanometers.