Nanocluster formation within the vapor plume, produced by nanosecond-laserablation: Effect of initial density and pressure distributions

The condensation of vapor in the expanding plume produced by ns-laser ablat ion is discussed within the framework of the Zeldovich and Raizer theory of condensation. The spherical plume expansion is described by a numerical so lution of the hydrodynamic equations by the cubic interpolated pseudo-parti cle (CIP) method. This permits us to analyze the role of initial distributi ons of density and pressure on the size distribution function of nanocluste rs. For parabolic distributions (for the plume expansion into vacuum), calc ulations reproduce the same results as those obtained by particular solutio ns of gas-dynamic equations. When initial distributions deviate from the pa rabolic distributions. the size distribution function varies. For the recta ngular plume, the size distribution function of nanoclusters demonstrates t wo maximums. A similar effect is observed due to the ambient gas influence.