Electromagnetic simulations of Raman amplification and magnetically-insulated transmission lines*

Raman Amplification is a novel method of amplifying a laser seed pulse in the presence of a specifically tuned pump pulse and background plasma generated from a laser-heated gas jet. The short-pulse laser amplification occurs in plasma which acts as an optical medium that provides gain but does not suffer from material degradation at high laser energies. The pump pulse energy is coupled to the seed pulse through electron plasma waves, resulting in much higher electric fields and laser intensities in the seed pulse. We report our efforts to simulate these novel amplification techniques in order to better explore the parameter space and find optimal setups for experimental designs. Additionally, we cover work related to simulating magnetically-insulated transmission lines (MITLs) used in high-energy Z-pinch machines, specifically for proving the numerical origin of non-physical electron vortices in the cathode emission region. These non-physical vortices are a product of the emission models used in most plasma software. The use of a smoothed-trigger emission model in addition to methods such as conformal geometry corrections for reducing staircase artifacts are explored to demonstrate the absence of the vortices usually found in simulations of Z-pinch MITLs.