title: Steplike intensity threshold behavior of extreme ionization in laser-driven xenon clusters.
abstract: The generation of highly charged Xe(q+) ions up to q=24 is observed in Xe clusters embedded in helium nanodroplets and exposed to intense femtosecond laser pulses (λ=800  nm). Laser intensity resolved measurements show that the high-q ion generation starts at an unexpectedly low threshold intensity of about 10(14)  W/cm2. Above threshold, the Xe ion charge spectrum saturates quickly and changes only weakly for higher laser intensities. Good agreement between these observations and a molecular dynamics analysis allows us to identify the mechanisms responsible for the highly charged ion production and the surprising intensity threshold behavior of the ionization process.
authors.affiliation: Institut für Physik, Universität Rostock, 18051 Rostock, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Döppner
authors.forename: J P
authors.initials: JP
authors.lastname: Müller
authors.forename: A
authors.initials: A
authors.lastname: Przystawik
authors.forename: S
authors.initials: S
authors.lastname: Göde
authors.forename: J
authors.initials: J
authors.lastname: Tiggesbäumker
authors.forename: K-H
authors.initials: KH
authors.lastname: Meiwes-Broer
authors.forename: C
authors.initials: C
authors.lastname: Varin
authors.forename: L
authors.initials: L
authors.lastname: Ramunno
authors.forename: T
authors.initials: T
authors.lastname: Brabec
authors.forename: T
authors.initials: T
authors.lastname: Fennel