Comment on the shape of the ionization cross section function for C60 + e → C+60 + 2e from threshold to maximum

Recently, Baba [M.S. Baba, T.S.L. Narasimhan, R. Balasubramanian and C.K. Mathews, Int. J. Mass Spectrom. Ion Processes, 114 (1992) R1] reported on the measured electron impact ionization cross section function for the production of C+60 and they noted a small peak situated at about 30 eV. In contrast, present measurements with an apparatus dedicated to the accurate determination of cross section functions reveals only a smoothly increasing function around this electron energy, thus excluding the existence of a possible resonance process in this energy region.