title: Time-resolved atomic inner-shell spectroscopy.
abstract: The characteristic time constants of the relaxation dynamics of core-excited atoms have hitherto been inferred from the linewidths of electronic transitions measured by continuous-wave extreme ultraviolet or X-ray spectroscopy. Here we demonstrate that a laser-based sampling system, consisting of a few-femtosecond visible light pulse and a synchronized sub-femtosecond soft X-ray pulse, allows us to trace these dynamics directly in the time domain with attosecond resolution. We have measured a lifetime of 7.9(-0.9)(+1.0) fs of M-shell vacancies of krypton in such a pump-probe experiment.
authors.affiliation: Institut für Photonik, Technische Universität Wien, Gusshausstrasse 27, A-1040 Wien, Austria. drescher@physik.uni-bielefeld.de
authors.forename: M
authors.initials: M
authors.lastname: Drescher
authors.forename: M
authors.initials: M
authors.lastname: Hentschel
authors.forename: R
authors.initials: R
authors.lastname: Kienberger
authors.forename: M
authors.initials: M
authors.lastname: Uiberacker
authors.forename: V
authors.initials: V
authors.lastname: Yakovlev
authors.forename: A
authors.initials: A
authors.lastname: Scrinzi
authors.forename: Th
authors.initials: T
authors.lastname: Westerwalbesloh
authors.forename: U
authors.initials: U
authors.lastname: Kleineberg
authors.forename: U
authors.initials: U
authors.lastname: Heinzmann
authors.forename: F
authors.initials: F
authors.lastname: Krausz