Simulation of channel formation through laser gas interaction*

Lasers of sufficient intensity passing through a neutral gas will ionize the gas creating a plasma channel in their wake. A shock can propagate from this locally heated region through the created plasma and background gas, however the density of the plasma will determine the dynamics of the plasma. For collisional (high density) plasmas this can be modelled with a fluid code, however a kinetic simulation is required for low collisionality. The Vorpal code [1] allows for self-consistent modelling of the laser pulse, plasma formation via field ionization, laser-plasma interaction, and subsequent plasma dynamics via particle-in-cell and EM simulation. It also includes a new reaction framework that enables the simulation of collisional dynamics such as elastic collisions, impact ionizations, and charge exchange reactions. We will show results for these laser-plasma interactions with varying gas/plasma densities spanning from highly collisional to collisionless regimes.

[1] C. Nieter and J. Cary. 2004. VORPAL: a versatile plasma simulation code. J. Comput. Phys. 196, 2, 448-473.