Cooling of pulsed laser-ablated plasma plume in an ambient gas and the onset condition of clustering in nanoparticle synthesis

The flow field in an ambient gas induced by pulsed-laser ablation of Si target surface was simulated numerically. To treat the Si particles in the evaporated gas and ambient gas separately, the CIP numerical method was used to track the interface of the two media. Appreciable interface instabilities were found which may enhance the mutual particle diffusion. This result shows a strong effect on the cooling of Si particles in the flow field. The degree of supersaturation was defined and the flow field was discussed to obtain the effects of the parameters on the clustering process.