An Application of the Laser-Induced Breakdown Method to Measurement of Carbon Particles Produced from the Laser Ablation of a Graphite Rod

The Laser-Induced Breakdown (LIB) method was applied to the measurement of the carbon particles produced in a jet which was expanded into vacuum, following the laser ablation of a graphite rod. The number density of the carbon particles and their sizedistribution down to approx. 200nm were estimated. From these results and further in considering the balance between the total mass of the carbon particles and the laser energy used for the ablation, two different mechanisms of particle formation are suggested. One mechanism is the strip-off of the particles directly from the graphite surface via ablation and the other is the growth to the particles from gaseous carbonaceous materials through a cluster stage.