title: Dissociative recombination of ammonia clusters studied by storage ring experiments.
abstract: Dissociative recombination of ammonia cluster ions with free electrons has been studied at the heavy-ion storage ring CRYRING (Manne Siegbahn Laboratory, Stockholm University). The absolute cross sections for dissociative recombination of H+(NH3)2, H+(NH3)3, D+(ND3)2, and D+(ND3)3 in the collision energy range of 0.001-27 eV are reported, and thermal rate coefficients for the temperature interval from 10 to 1000 K are calculated from the experimental data and compared with earlier results. The fragmentation patterns for the two ions H+(NH3)2 and D+(ND3)2 show no clear isotope effect. Dissociative recombination of X+(NX3)2 (X=H or D) is dominated by the product channels 2NX3+X [0.95+/-0.02 for H+(NH3)2 and 1.00+/-0.02 for D+(ND3)2]. Dissociative recombination of D+(ND3)3 is dominated by the channels yielding three N-containing fragments (0.95+/-0.05).
authors.affiliation: Department of Chemistry, Atmospheric Science, Göteborg University, SE-412 96 Göteborg, Sweden.
authors.forename: J
authors.initials: J
authors.lastname: Ojekull
authors.forename: P U
authors.initials: PU
authors.lastname: Andersson
authors.forename: M B
authors.initials: MB
authors.lastname: Någård
authors.forename: J B C
authors.initials: JB
authors.lastname: Pettersson
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authors.initials: A
authors.lastname: Neau
authors.forename: S
authors.initials: S
authors.lastname: Rosén
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authors.initials: RD
authors.lastname: Thomas
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authors.lastname: Larsson
authors.forename: J
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authors.lastname: Semaniak
authors.forename: F
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authors.lastname: Osterdahl
authors.forename: H
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authors.lastname: Danared
authors.forename: A
authors.initials: A
authors.lastname: Källberg
authors.forename: M af
authors.initials: Ma
authors.lastname: Ugglas