Probe detection of charged coarsely dispersed carbon particles upon laser ablation of pyrolytic graphite

The mass distribution of charged particles from the plasma plume produced by laser ablation of pyrolytic graphite was studied by an electrostatic probe technique. The velocities of motion of the charged opposite parts of the plume double-electric layer and the potential of its internal self-consistent field were determined. Using a proposed procedure for the treatment of probe signals, the amounts of detectable positive and negative ions were evaluated. The negatively charged large carbon particles with a size of up to 10(6) atoms were assumed to directly appear from explosive bulk effervescence and spinodal separation of the overheated carbon phase on the graphite surface.