title: Near-threshold inelastic collisions using molecular beams with a tunable velocity.
abstract: Molecular scattering behavior has generally proven difficult to study at low collision energies. We formed a molecular beam of OH radicals with a narrow velocity distribution and a tunable absolute velocity by passing the beam through a Stark decelerator. The transition probabilities for inelastic scattering of the OH radicals with Xe atoms were measured as a function of the collision energy in the range of 50 to 400 wavenumbers, with an overall energy resolution of about 13 wavenumbers. The behavior of the cross-sections for inelastic scattering near the energetic thresholds was accurately measured, and excellent agreement was obtained with cross-sections derived from coupled-channel calculations on ab initio computed potential energy surfaces.
authors.affiliation: Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany.
authors.forename: Joop J
authors.initials: JJ
authors.lastname: Gilijamse
authors.forename: Steven
authors.initials: S
authors.lastname: Hoekstra
authors.forename: Sebastiaan Y T
authors.initials: SY
authors.lastname: van de Meerakker
authors.forename: Gerrit C
authors.initials: GC
authors.lastname: Groenenboom
authors.forename: Gerard
authors.initials: G
authors.lastname: Meijer