Rate-coefficients and polarization results for the electron-impact excitation of Ar$^{+}$ ion

A fully relativistic distorted wave theory has been employed to study the electron impact excitation in Ar$^{+}$ ion. Results have been obtained for the excitation cross-sections and rate-coefficients for the transitions from the ground state 3$p^{5}$ ($J=$3/2) to fine-structure levels of excited states 3$p^{4}$4$s$, 3$p^{4}$4$p, $3$p^{4}$5$s$, 3$p^{4}$5$p$, 3$p^{4}$3$d$ and 3$p^{4}$4$d$. Polarization of the radiation following the excitation has been calculated using the obtained magnetic sub-level cross-sections. Comparison of the present rate-coefficients is also done with the previously reported theoretical results for some unresolved fine structure transitions.