title: X-ray microprobe of orbital alignment in strong-field ionized atoms.
abstract: We have developed a synchrotron-based, time-resolved x-ray microprobe to investigate optical strong-field processes at intermediate intensities (10(14) - 10(15) W/cm2). This quantum-state specific probe has enabled the direct observation of orbital alignment in the residual ion produced by strong-field ionization of krypton atoms via resonant, polarized x-ray absorption. We found strong alignment to persist for a period long compared to the spin-orbit coupling time scale (6.2 fs). The observed degree of alignment can be explained by models that incorporate spin-orbit coupling. The methodology is applicable to a wide range of problems.
authors.affiliation: Argonne National Laboratory, Argonne, Illinois 60439, USA. young@anl.gov
authors.forename: L
authors.initials: L
authors.lastname: Young
authors.forename: D A
authors.initials: DA
authors.lastname: Arms
authors.forename: E M
authors.initials: EM
authors.lastname: Dufresne
authors.forename: R W
authors.initials: RW
authors.lastname: Dunford
authors.forename: D L
authors.initials: DL
authors.lastname: Ederer
authors.forename: C
authors.initials: C
authors.lastname: Höhr
authors.forename: E P
authors.initials: EP
authors.lastname: Kanter
authors.forename: B
authors.initials: B
authors.lastname: Krässig
authors.forename: E C
authors.initials: EC
authors.lastname: Landahl
authors.forename: E R
authors.initials: ER
authors.lastname: Peterson
authors.forename: J
authors.initials: J
authors.lastname: Rudati
authors.forename: R
authors.initials: R
authors.lastname: Santra
authors.forename: S H
authors.initials: SH
authors.lastname: Southworth