title: Fragmentation branching ratios of highly excited hydrocarbon molecules CnH and their cations CnH+ (n<or=4).
abstract: We have measured fragmentation branching ratios of neutral C(n)H and C(n)H(+) cations produced in high velocity (4.5 a.u) collisions between incident C(n)H(+) cations and helium atoms. Electron capture gives rise to excited neutral species C(n)H and electronic excitation to excited cations C(n)H(+). Thanks to a dedicated setup, based on coincident detection of all fragments, the dissociations of the neutral and cationic parents were recorded separately and in a complete way. For the fragmentation of C(n)H, the H-loss channel is found to be dominant, as already observed by other authors. By contrast, the H-loss and C-loss channels equally dominate the two-fragment break up of C(n)H(+) species. For these cations, we provide the first fragmentation data (n>2). Results are also discussed in the context of astrochemistry.
authors: Institut de Physique Nucléaire, CNRS-IN2P3 and Université Paris-Sud, 91405 Orsay Cedex, France.
authors: T
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authors: Tuna
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authors: Chabot
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authors: Pino
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authors: Désesquelles
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authors: LePadellec
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authors: Martinet
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authors: Barat
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authors: Lucas
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authors: Mezdari
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authors: Montagnon
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authors: Van-Oanh
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authors: Lavergne
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authors: Lachaize
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authors: Carpentier
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authors: Béroff