Two-body Coulomb explosion in methylacetylene in intense laser fields: double proton migration and proton/deuteron exchange

摘要

Two-body decomposition processes of methylacetylene (CH3CCH) and its isotopomer methyl-d3-acetylene (CD3CCH) in intense laser fields (790 nm, 40 fs, 5.0 x 10~(13) W cm~(-2)) are investigated by the coincidence momentum imaging (CMI). In methyl-d3-acetylene, a total of six decomposition pathways in which one of the C—C bonds is broken and a total of six pathways in which an atomic hydrogen ion (H~+ or D~+) or a molecular hydrogen ion (H~(2+), HD~+, D_3~+, or HD_2~+) is ejected are identified. It is revealed from the analysis of the CMI data that the migration of two deuterons as well as the exchange between a proton and a deuteron occurs prior to the two-body decomposition of a doubly charged parent molecule.