Benchmark calculation of electron-impact ionization cross sections and rate coefficients of atomic ions in Ar isonuclear sequence

Argon is being considered as an injected impurity to mitigate damage to divertors of DEMO caused by excessive heat flux. For a comprehensive understanding of Ar plasma, carefully evaluated atomic data are required. In this study, the electron-impact ionization cross-sections and rate coefficients for all atomic ions in the argon isonuclear sequence are calculated using the level-to-level distorted wave approximation. The calculated cross-sections and rate coefficients are compared with experimental data and other theoretical calculations. The calculated values are consistent with results reported in the literature, with differences not exceeding 20%. We fit the calculated cross-sections using an empirical formula. Additionally, we combine our ionization rate coefficients with the dielectronic- and radiative-recombination rate coefficients from other studies to determine the ionization balance. The obtained data are expected to be useful for plasma modelling involving argon impurities.