Plasma formation on a metal surface under combined action of laser and microwave radiation

By means of numerical modelling of the combined effect of laser (1.06 mm) and microwave (10¹⁰ – 10¹³ s^-1) radiation on the aluminium surface in vacuum it is shown that the additional action of microwave radiation with the frequency 10¹² s^-1 provides complete ionisation of the metal vapour (for the values of laser radiation duration and intensity used in the calculations), while in the absence of microwave radiation the vapour remains weakly ionised. The mathematical model used accounts for the processes, occurring in the condensed phase (heat conduction, melting), the evaporation and the kinetic processes in the resulting vapour.