“…They consist of a large number of processes that directly depend on atomic state densities, e.g., collisional excitation/deexcitation, ionization/recombination, autoionization/electron capture, photo-ionization and radiative recombination. Detailed expressions for these terms are given in appendix A. Time-dependent Boltzmann kinetic model had been used in the past to simulate ultrashort-pulse high intensity laser experiments (see, for example, [7][8][9]). These studies often assume a spatially homogenous (zero-dimensional) plasma to simplify the calculation.…”