title: Electron diffraction self-imaging of molecular fragmentation in two-step double ionization of water.
abstract: We doubly ionize H(2)O by single photon absorption at 43 eV leading to H(+) + OH(+). A direct double ionization and a sequential process in which single ionization is followed by rapid dissociation into a proton and an autoionizing OH(*) are identified. The angular distribution of this delayed autoionization electron shows a preferred emission in the direction of the emitted proton. From this diffraction feature we obtain internuclear distances of 700 to 1100 a.u. at which the autoionization of the OH(*) occurs. The experimental findings are in line with calculations of the excited potential energy surfaces and their lifetimes.
authors.affiliation: Institut für Kernphysik, J. W. Goethe Universität, Max-von-Laue-Str. 1, 60438 Frankfurt, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Sann
authors.forename: T
authors.initials: T
authors.lastname: Jahnke
authors.forename: T
authors.initials: T
authors.lastname: Havermeier
authors.forename: K
authors.initials: K
authors.lastname: Kreidi
authors.forename: C
authors.initials: C
authors.lastname: Stuck
authors.forename: M
authors.initials: M
authors.lastname: Meckel
authors.forename: M S
authors.initials: MS
authors.lastname: Schöffler
authors.forename: N
authors.initials: N
authors.lastname: Neumann
authors.forename: R
authors.initials: R
authors.lastname: Wallauer
authors.forename: S
authors.initials: S
authors.lastname: Voss
authors.forename: A
authors.initials: A
authors.lastname: Czasch
authors.forename: O
authors.initials: O
authors.lastname: Jagutzki
authors.forename: Th
authors.initials: T
authors.lastname: Weber
authors.forename: H
authors.initials: H
authors.lastname: Schmidt-Böcking
authors.forename: S
authors.initials: S
authors.lastname: Miyabe
authors.forename: D J
authors.initials: DJ
authors.lastname: Haxton
authors.forename: A E
authors.initials: AE
authors.lastname: Orel
authors.forename: T N
authors.initials: TN
authors.lastname: Rescigno
authors.forename: R
authors.initials: R
authors.lastname: Dörner