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Author Larson, A. ♦ Le Padellec, A. ♦ Semaniak, J. ♦ Stroemholm, C. ♦ Larsson, M. ♦ Rosen, S. ♦ Peverall, R. ♦ Danared, H. ♦ Djuric, N. ♦ Dunn, G. H. ♦ Datz, S.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword PHYSICS ♦ CARBON COMPOUNDS ♦ HYDROGEN COMPOUNDS ♦ CROSS SECTIONS ♦ COSMOCHEMISTRY ♦ CHEMICAL COMPOSITION ♦ INTERSTELLAR SPACE ♦ ION-MOLECULE COLLISIONS ♦ HYDROCARBONS ♦ DISSOCIATION ♦ RECOMBINATION ♦ MOLECULES ♦ MOLECULAR PROCESSES
Abstract The absolute cross section and branching ratios for dissociative recombination of CH{sup {plus}} {sub 2} with electrons have been measured by means of the heavy-ion storage ring CRYRING. Contrary to what has been previously believed, recombination of CH{sup {plus}} {sub 2} is dominated by the three-body channel C + H + H (63{percent}), whereas breakup into the CH + H and C + H{sub 2} channels occurs with branching ratios of 25{percent} and 12{percent}, respectively. The thermal rate coefficient for dissociative recombination at 300 K is 6.4 {times} 10{sup {minus}7} cm{sup 3} s{sup {minus}1}, which is higher by a factor of 2.5 than the value used in modeling dark molecular clouds. The low CH production and the high production of energetic carbon atoms could be favorable factors for the turbulence model to explain the large abundance of interstellar CH{sup +}. The cross section for dissociative excitation was also measured and found to be in good agreement with results from a crossed electron-ion beam experiment. {copyright} {ital {copyright} 1998.} {ital The American Astronomical Society}
ISSN 0004637X
Educational Use Research
Learning Resource Type Article
Publisher Date 1998-09-01
Publisher Place United States
Journal Astrophysical Journal
Volume Number 505
Issue Number 1


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