title: Electron impact ionization in the presence of a laser field: a kinematically complete (ngammae,2e) experiment.
abstract: Single ionization of He by 1 keV electron impact in the presence of an intense (I=4 x 10(12) W/cm(2)) laser field (lambda=1064 nm) has been explored in a kinematically complete experiment using a reaction microscope. Distinct differences in the singly to fully differential cross sections compared to the field-free situation are observed which cannot be explained by a first-order quantum calculation. Major features, such as the number of photons exchanged and the modification of the energy spectrum of emitted electrons, can be understood qualitatively within a simple classical model.
authors.affiliation: Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Höhr
authors.forename: A
authors.initials: A
authors.lastname: Dorn
authors.forename: B
authors.initials: B
authors.lastname: Najjari
authors.forename: D
authors.initials: D
authors.lastname: Fischer
authors.forename: C D
authors.initials: CD
authors.lastname: Schröter
authors.forename: J
authors.initials: J
authors.lastname: Ullrich