Fig. 1

Fig. 2

Fig. 3

Fig. 4

Fig. 5

Comments: Judging from the unnormalized spectra (figs 4-5) C +, CH + and C 2 + (possibly also slight H + (?)) are formed in excitation via the A state (i.e. A<-X resonance excitation) Judging from the normalized spectra (figs. 1-3) relatively more C 2 + (compared to C + and CH + ) is formed via A state excitation compared to nonresonant transition NB!: the A<-X spectrum is a weak signal (1+ n)REMPI, hence it is observed for strong LASER power only, in which case large nonresonant component can be expected.