title: Photoelectric effect at ultrahigh intensities.
abstract: In the spectral range of the extreme ultraviolet at a wavelength of 13.3 nm, we have studied the photoionization of xenon at ultrahigh intensities. For our ion mass-to-charge spectroscopy experiments, irradiance levels from 10(12) to 10(16) W cm(-2) were achieved at the new free-electron laser in Hamburg FLASH by strong beam focusing with the aid of a spherical multilayer mirror. Ion charges up to Xe21+ were observed and investigated as a function of irradiance. Our surprising results are discussed in terms of a perturbative and nonperturbative description.
authors.affiliation: Physikalisch-Technische Bundesanstalt, Abbestrasse 2-12, D-10587 Berlin, Germany.
authors.forename: A A
authors.initials: AA
authors.lastname: Sorokin
authors.forename: S V
authors.initials: SV
authors.lastname: Bobashev
authors.forename: T
authors.initials: T
authors.lastname: Feigl
authors.forename: K
authors.initials: K
authors.lastname: Tiedtke
authors.forename: H
authors.initials: H
authors.lastname: Wabnitz
authors.forename: M
authors.initials: M
authors.lastname: Richter