title: Extreme ultraviolet ionization of pure He nanodroplets: mass-correlated photoelectron imaging, Penning ionization, and electron energy-loss spectra.
abstract: The ionization dynamics of pure He nanodroplets irradiated by Extreme ultraviolet radiation is studied using Velocity-Map Imaging PhotoElectron-PhotoIon COincidence spectroscopy. We present photoelectron energy spectra and angular distributions measured in coincidence with the most abundant ions He(+), He2(+), and He3(+). Surprisingly, below the autoionization threshold of He droplets, we find indications for multiple excitation and subsequent ionization of the droplets by a Penning-like process. At high photon energies we observe inelastic collisions of photoelectrons with the surrounding He atoms in the droplets.
authors.affiliation: Physikalisches Institut, Universität Freiburg, 79104 Freiburg, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Buchta
authors.forename: S R
authors.initials: SR
authors.lastname: Krishnan
authors.forename: N B
authors.initials: NB
authors.lastname: Brauer
authors.forename: M
authors.initials: M
authors.lastname: Drabbels
authors.forename: P
authors.initials: P
authors.lastname: O'Keeffe
authors.forename: M
authors.initials: M
authors.lastname: Devetta
authors.forename: M
authors.initials: M
authors.lastname: Di Fraia
authors.forename: C
authors.initials: C
authors.lastname: Callegari
authors.forename: R
authors.initials: R
authors.lastname: Richter
authors.forename: M
authors.initials: M
authors.lastname: Coreno
authors.forename: K C
authors.initials: KC
authors.lastname: Prince
authors.forename: F
authors.initials: F
authors.lastname: Stienkemeier
authors.forename: J
authors.initials: J
authors.lastname: Ullrich
authors.forename: R
authors.initials: R
authors.lastname: Moshammer
authors.forename: M
authors.initials: M
authors.lastname: Mudrich