title: Soft x-ray laser spectroscopy on trapped highly charged ions at FLASH.
abstract: In a proof-of-principle experiment, we demonstrate high-resolution resonant laser excitation in the soft x-ray region at 48.6 eV of the 2 (2)S(1/2) to 2 (2)P(1/2) transition of Li-like Fe23+ ions trapped in an electron beam ion trap by using ultrabrilliant light from Free Electron Laser in Hamburg (FLASH). High precision spectroscopic studies of highly charged ions at this and upcoming x-ray lasers with an expected accuracy gain up to a factor of a thousand, become possible with our technique, thus potentially yielding fundamental insights, e.g., into basic aspects of QED.
authors.affiliation: Max-Planck-Institut für Kernphysik, D-69117 Heidelberg, Germany. epp@mpi-hd.mpg.de
authors.forename: S W
authors.initials: SW
authors.lastname: Epp
authors.forename: J R Crespo
authors.initials: JR
authors.lastname: López-Urrutia
authors.forename: G
authors.initials: G
authors.lastname: Brenner
authors.forename: V
authors.initials: V
authors.lastname: Mäckel
authors.forename: P H
authors.initials: PH
authors.lastname: Mokler
authors.forename: R
authors.initials: R
authors.lastname: Treusch
authors.forename: M
authors.initials: M
authors.lastname: Kuhlmann
authors.forename: M V
authors.initials: MV
authors.lastname: Yurkov
authors.forename: J
authors.initials: J
authors.lastname: Feldhaus
authors.forename: J R
authors.initials: JR
authors.lastname: Schneider
authors.forename: M
authors.initials: M
authors.lastname: Wellhöfer
authors.forename: M
authors.initials: M
authors.lastname: Martins
authors.forename: W
authors.initials: W
authors.lastname: Wurth
authors.forename: J
authors.initials: J
authors.lastname: Ullrich
mesh_terms: D007477:Ions; D007501:Iron / Q000737:chemistry; D007834:Lasers; D017785:Photons; D013052:Spectrometry, X-Ray Emission / Q000379:methods*; D014965:X-Rays
chemical_list: D007477:Ions; D007501:Iron