Flows dynamics in pulse electrothermal launcher with multigap scheme of discharge unit

A multigap scheme of the electrothermal launcher discharge unit is proposed with the purpose to obtain super high quality coatings out of powder materials. The theoretical analysis of the flow dynamics and particles acceleration has shown that such a scheme makes it possible to form the microparticle acceleration region with required parameters. In turn it permits to increase the dimensional range of microparticles to be accelerated up to 40-50 /spl mu/m while preserving high values of their velocity (1.5/spl divide/2 km/s). The experimental study of the flow dynamics in the electrothermal launcher which contains two discharge gaps positioned at some distance along the barrel confirmed the theoretical conclusion. In particular, two-fold increase of the shock-wave velocity behind the second gap was observed. In addition, the shock compressed gas region length has been diminished whereas the gas mass in that region was increased more than twice.