title: Three-dimensional images for electron-impact single ionization of He: complete and comprehensive (e, 2e) benchmark data.
abstract: Comprehensive fully differential cross sections for electron emission into all three spatial dimensions are presented for 1 keV and 102 eV electron-impact single ionization of helium using an advanced reaction microscope. Surprising out-of-plane contributions, traced back to an interference term in a perturbation expansion by comparison with ion-impact data, severely challenge theoretical models that accurately predict coplanar emission. The data represent the ultimate benchmark for recently developed exact theoretical descriptions of the most fundamental three-body quantum problems.
authors.affiliation: Max-Planck-Institute for Nuclear Physics, Saupfercheckweg 1, 69117 Heidelberg, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Dürr
authors.forename: C
authors.initials: C
authors.lastname: Dimopoulou
authors.forename: B
authors.initials: B
authors.lastname: Najjari
authors.forename: A
authors.initials: A
authors.lastname: Dorn
authors.forename: J
authors.initials: J
authors.lastname: Ullrich