Ekectron-Impact Excitation of C$^+$

Electron-impact excitation cross sections are calculated for ground and excited states of C$^+$ using the R-matrix with pseudo-states method. We used the configurations $1s^2 2s^2 nl (3s \leq nl \leq 12g)$, $1s^2 2s 2p nl (2p \leq nl \leq 12g)$, $1s^2 2p^2 nl (2p \leq nl \leq 12g)$, $1s^2 2s 3s^2$, and $1s^2 2s 3d^2$, resulting in 890 LS terms and 2048 LSJ levels. Excitation cross sections for the $1s^2 2s^2 2p \ ^2P \rightarrow \ ^4P, ^2D, ^2S$ transitions are in good agreement with experiment. Combined with previous calculations for C and C$^{q+}$ ($q = 2-5$), sufficient excitation, ionization, and recombination atomic data is now available to generate high quality collisional-radiative coefficients for the entire C isonuclear sequence.