High-resolution dissociative recombination of cold H3+and first evidence for nuclear spin effects

• Published in: Physical review letters Vol. 95; no. 26; p. 263201
• Main Authors: Kreckel, H, Motsch, M, Mikosch, J, Glosík, J, Plasil, R, Altevogt, S, Andrianarijaona, V, Buhr, H, Hoffmann, J, Lammich, L, Lestinsky, M, Nevo, I, Novotny, S, Orlov, D A, Pedersen, H B, Sprenger, F, Terekhov, A S, Toker, J, Wester, R, Gerlich, D, Schwalm, D, Wolf, A, Zajfman, D
• Format: Journal Article
• Language: English
• Published: United States 31-12-2005
• ISSN: 0031-9007
• DOI: 10.1103/PhysRevLett.95.263201

The energy-resolved rate coefficient for the dissociative recombination (DR) of H(3)(+) with slow electrons has been measured by the storage-ring method using an ion beam produced from a radiofrequency multipole ion trap, employing buffer-gas cooling at 13 K. The electron energy spread of the merged-beams measurement is reduced to 500 microeV by using a cryogenic GaAs photocathode. This and a previous cold- measurement jointly confirm the capability of ion storage rings, with suitable ion sources, to store and investigate H(3)(+) in the two lowest, (J,G) = (1,1) and (1,0) rotational states prevailing also in cold interstellar matter. The use of para-H(2) in the ion source, expected to enhance para-H(3)(+) in the stored ion beam, is found to increase the DR rate coefficient at meV electron energies.