Pulsed laser evaporation: equationofstate effects
Abstract
Theoretical study of laser ablation is usually based on the assumption that the vapor is an ideal gas. Its flow is described by gas dynamics equations [1, 2]. The boundary conditions at vaporization front are derived from the solution of the Boltzmann equation that describes the vapor flow in the immediate vicinity of the vaporizing surface (socalled Knudsen layer) [1]. This model is applicable within the range of temperatures much lower than the critical temperature of target material. In the present work, a general case is considered when the temperature of the condensed phase is comparable to or higher than the critical temperature. The dynamics of both condensed and gaseous phases can be described in this case by the equations of hydrodynamics. The dynamics of vaporization of a metal heated by an ultrashort laser pulse is studied both analytically and numerically. The analysis reveals that the flow consists of two domains: thin liquid shell moving with constant velocity, and thick lowdensity layer of material in twophase state.
 Publication:

Applied Physics A: Materials Science & Processing
 Pub Date:
 1999
 DOI:
 10.1007/s003390051041
 Bibcode:
 1999ApPhA..69..617A
 Keywords:

 PACS: 81.60Z;
 65.70.+y;
 64.60.Ht