Simulation of Laser Plasma Dynamics: Influence of Ambient Pressure and Intensity of Laser Radiation

✍ Scribed by V. Mazhukin; I. Smurov; G. Flamant

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 567 KB
• Volume: 112
• Category: Article
• ISSN: 0021-9991
• DOI: 10.1006/jcph.1994.1082

✦ Synopsis

A mathematical model, describing the dynamics of laser plasma (gas dynamic stage) in air medium with the pressure variation in the range of 1-100 Bar, is presented. The simulation is based on the transient axially symmetric system of radiative gas dynamic equations. The application on the multi-group diffusion approximation for the simulation of radiation transfer is discussed. The solution of gas dynamic equations is made by the explicit finite-difference FLIC method. For the energy equation solving jointly with the averaged equation of radiation diffusion, the implicit difference scheme is used. The later is realized by the proposed nonlinear iterative procedure. The evolution of laser plasma in the near threshold values (for plasma formation) of radiation intensity (G=5 \times 10^{7}-5 \times 10^{8} \mathrm{~W} / \mathrm{cm}^{2}(\lambda=1.06 \mu \mathrm{m})) is analyzed. It is shown that the mechanism of the plasma expansion strongly depends on the pressure of the gaseous medium: it varies from the light detonation regime of fast combustion at low pressures; to the slow combustion in the form of the subsonic radiative wave at high pressures. 'C' 1994 Academic Press, Inc.