title: Fragmentation of metastable SF(6)(-*) ions with microsecond lifetimes in competition with autodetachment.
abstract: Fragmentation of metastable SF(6)(-*) ions formed in low energy electron attachment to SF(6) has been investigated. The dissociation reaction SF(6)(-*)-->SF(5) (-)+F has been observed approximately 1.5-3.4 micros and approximately 17-32 micros after electron attachment in a time-of-flight and a double focusing two sector field mass spectrometer, respectively. Metastable dissociation is observed with maximum intensity at approximately 0.3 eV between the SF(6)(-*) peak at zero and the SF(5)(-) peak at approximately 0.4 eV. The kinetic energy released in dissociation is low, with a most probable value of 18 meV. The lifetime of SF(6)(-*) decreases as the electron energy increases, but it is not possible to fit this decrease with statistical Rice-Ramsperger-Kassel/quasiequilibrium theory. Metastable dissociation of SF(6)(-*) appears to compete with autodetachment of the electron at all electron energies.
authors.affiliation: Centre for Plasma Physics, School of Mathematics and Physics, Queen's University Belfast, Belfast, UK.
authors.forename: K
authors.initials: K
authors.lastname: Graupner
authors.forename: T A
authors.initials: TA
authors.lastname: Field
authors.forename: A
authors.initials: A
authors.lastname: Mauracher
authors.forename: P
authors.initials: P
authors.lastname: Scheier
authors.forename: A
authors.initials: A
authors.lastname: Bacher
authors.forename: S
authors.initials: S
authors.lastname: Denifl
authors.forename: F
authors.initials: F
authors.lastname: Zappa
authors.forename: T D
authors.initials: TD
authors.lastname: Märk