title: Observation of large quadrupolar effects in a slow photoelectron imaging experiment.
abstract: We have studied nondipolar effects in resonance-enhanced multiphoton ionization of Xe and have observed an azimuthal dependence of the photoelectron angular distribution on a quadrupole resonance, as well as a very large asymmetry with respect to the direction of the laser propagation close to the resonance, which is understood in terms of interference between dipole- and quadrupole-allowed ionization channels. The observed asymmetry in the photoelectron angular distribution provides insight into the ejection of slow photoelectrons near an ionization threshold.
authors.affiliation: FOM Institute for Atomic and Molecular Physics (AMOLF), Kruislaan 407, 1098 SJ Amsterdam, The Netherlands.
authors.forename: F
authors.initials: F
authors.lastname: Lépine
authors.forename: S
authors.initials: S
authors.lastname: Zamith
authors.forename: A
authors.initials: A
authors.lastname: de Snaijer
authors.forename: Ch
authors.initials: Ch
authors.lastname: Bordas
authors.forename: M J J
authors.initials: MJ
authors.lastname: Vrakking