Abstract:
Complete collisional-radiative model describing the kinetics of nonequilibrium ionization of atoms and ions of metal by laser irradiation was developed. The kinetics model include collisional reactions: electron excitation and deexcitation, cascade ionization and recombination, spontaneous decay of excited states and also photo processes: photoexcitation and deexcitation, photoionization and photorecombination in the laser field and continued irradiation. It allows to use suggesting model for the investigation of optical break-down of metal vapors in wide spectral range of acting irradiation.
Optical breakdown of aluminum vapor was considered and spectral dependence of threshold intensity of laser irradiation $G^*(\omega_\ell)$ in the wave range $\lambda_\ell=10\div0,1\mu m$ was defined. Primary mechanisms of the breakdown in IR, visible and UF ranges of the irradiation under unlimited act duration were defined.