Numerical studies of the momentum transfer in inverse Bremsstrahlung absorption

The laser momentum absorption due to inverse Bremsstrahlung is studied numerically using test particle Monte Carlo and molecular dynamics simulations. The difference between numerical simulations that treat momentum absorption correctly and the ones that treat only energy absorption correctly is emphasized. The results are compared with the analytical predictions, specifically that the average momentum absorption rate of the electrons is higher than the naive estimates suggest, due to the recoil momentum from the ions.