Pathways for nonsequential and sequential fragmentation of CO23+ investigated by electron collision

We report nonsequential and sequential fragmentation dynamics of CO23+ investigated by electron collision at an impact energy of 500 eV. The dissociation mechanisms are clearly distinguished by combined use of the Dalitz plot together with momentum correlation spectra. The angular distributions and kinetic-energy releases (KERs) of different fragmentation processes are obtained. The dissociation channels of higher excited states of the CO23+ molecular ion are opened, which are quite different from the previous studies of heavy-ion collision [N. Neumann, D. Hant, L. Ph. H. Schmidt, J. Titze, T. Jahnke, A. Czasch, M. S. Schoffler, K. Kreidi, O. Jagutzki, H. Schmidt-Bocking, and R. Dorner, Phys. Rev. Lett. 104, 103201 (2010)] and intense laser field [C. Wu, C. Wu, D. Song, H. Su, Y. Yang, Z. Wu, X. Liu, H. Liu, M. Li, Y. Deng, Y. Liu, L.-Y. Peng, H. Jiang, and Q. Gong, Phys. Rev. Lett. 110, 103601 (2013)]. By analyzing KERs together with the help of potential-energy curves exploration at the multireference configuration interaction level, we conclude that the sequential fragmentation occurs in the (2)Pi, (4)Pi, and (2)Sigma(+) states of the CO23+ ion. The bond length and bond angle are also determined based on the linear fragmentation, indicating that electron impact fragmentation is a potential method to precisely reconstruct the geometry of neutral molecules.