Particle Movement in a Dusty RF Plasma at Power Switch-OFF

Particles are generated in a capacitive radiofrequency methane-nitrogen discharge. Forces act on them; they levitate and form two clouds at the sheath boundaries close to the electrodes. In each cloud, particle size segregation is observed. At the plasma extinction, dust particle clouds show different movements. In addition, particle movement within each cloud depends on the particle size. The movements are due to the plasma extinction, the electrostatic interaction between clouds and the particle residual charge.