The Investigation of Plasma Produced by Intense Nanosecond Laser Ablation in Vacuum Under External Magnetic Field Using a Two Stage Model

Abstract

In this paper a twostage physicsbased model has been applied to study the evolution of plasma produced by highintensity nanosecond laser ablation in vacuum under external magnetic field. In the early stage (Stage I), the laserinduced plasma generation and its shortterm evolution are described through onedimensional (1D) hydrodynamic equations. An equation of state (EOS) that can cover the density and temperature range in the whole physical domain has been applied to supplement the hydrodynamic equations. In the later stage (Stage II), the plasma longterm evolution is simulated by solving 2D gas dynamic equations. The twostage model can predict the spatial distributions and temporal evolutions of plasma temperature, density, velocity, and other parameters. The model is used to study and discuss the effects of external magnetic field on the plasma evolution. It provides a useful tool for related fundamental studies and practical applications.