title: Strongly enhanced backward emission of electrons in transfer and ionization.
abstract: We studied three-dimensional angular distributions and longitudinal momentum spectra of electrons ejected in transfer plus ionization (TI), i.e., the ejection of one and the capture of a second target electron, for ion-helium collisions. We observe a pronounced structure strongly focused opposite to the projectile beam direction, which we associate with a new correlated TI mechanism proposed recently. This process contributes significantly to the total cross sections over a broad range of perturbations η, even at η as large as 0.5, where uncorrelated TI mechanisms were thought to be dominant.
authors.affiliation: Physics Department and LAMOR, Missouri University of Science & Technology, Rolla, Missouri 65409, USA.
authors.forename: M
authors.initials: M
authors.lastname: Schulz
authors.forename: X
authors.initials: X
authors.lastname: Wang
authors.forename: M
authors.initials: M
authors.lastname: Gundmundsson
authors.forename: K
authors.initials: K
authors.lastname: Schneider
authors.forename: A
authors.initials: A
authors.lastname: Kelkar
authors.forename: A B
authors.initials: AB
authors.lastname: Voitkiv
authors.forename: B
authors.initials: B
authors.lastname: Najjari
authors.forename: M
authors.initials: M
authors.lastname: Schöffler
authors.forename: L Ph H
authors.initials: LP
authors.lastname: Schmidt
authors.forename: R
authors.initials: R
authors.lastname: Dörner
authors.forename: J
authors.initials: J
authors.lastname: Ullrich
authors.forename: R
authors.initials: R
authors.lastname: Moshammer
authors.forename: D
authors.initials: D
authors.lastname: Fischer