Time-dependent calculations of electron energy distribution functions for neon gas in the presence of intense XFEL radiation

Boltzmann electron kinetic simulations are performed to study the time development of the electron energy distribution function (EEDF) in plasma resulting from neon gas subject to a 40 fs x-ray free electron laser radiation source. The simulations are performed without any assumptions of electron temperature. The distributions are calculated as a function of time through 40 fs using Boltzmann kinetics, including the appropriate processes that alter state populations and electron energy. The calculations are also extended into the picosecond regime, after the laser pulse, to track the thermalization of free electrons. Results are presented that predict the evolution of the charge-state distribution, effective temperature, the photon spectrum, as well as the EEDF