title: Hetero-site-specific X-ray pump-probe spectroscopy for femtosecond intramolecular dynamics.
abstract: New capabilities at X-ray free-electron laser facilities allow the generation of two-colour femtosecond X-ray pulses, opening the possibility of performing ultrafast studies of X-ray-induced phenomena. Particularly, the experimental realization of hetero-site-specific X-ray-pump/X-ray-probe spectroscopy is of special interest, in which an X-ray pump pulse is absorbed at one site within a molecule and an X-ray probe pulse follows the X-ray-induced dynamics at another site within the same molecule. Here we show experimental evidence of a hetero-site pump-probe signal. By using two-colour 10-fs X-ray pulses, we are able to observe the femtosecond time dependence for the formation of F ions during the fragmentation of XeF2 molecules following X-ray absorption at the Xe site.
authors.affiliation: Argonne National Laboratory, Argonne, Illinois 60439, USA.
authors.forename: A
authors.initials: A
authors.lastname: Picón
authors.affiliation: Argonne National Laboratory, Argonne, Illinois 60439, USA.
authors.forename: C S
authors.initials: CS
authors.lastname: Lehmann
authors.affiliation: Argonne National Laboratory, Argonne, Illinois 60439, USA.|Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60208, USA.
authors.forename: C
authors.initials: C
authors.lastname: Bostedt
authors.affiliation: J.R. Macdonald Laboratory, Department of Physics, Kansas State University, Manhattan, Kansas 66506, USA.
authors.forename: A
authors.initials: A
authors.lastname: Rudenko
authors.affiliation: SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA.
authors.forename: A
authors.initials: A
authors.lastname: Marinelli
authors.affiliation: SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA.
authors.forename: T
authors.initials: T
authors.lastname: Osipov
authors.affiliation: J.R. Macdonald Laboratory, Department of Physics, Kansas State University, Manhattan, Kansas 66506, USA.|Deutsches Elektronen-Synchrotron (DESY), Hamburg 22607, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Rolles
authors.affiliation: Department of Physics, University of Connecticut, Storrs, Connecticut 06269, USA.
authors.forename: N
authors.initials: N
authors.lastname: Berrah
authors.affiliation: Deutsches Elektronen-Synchrotron (DESY), Hamburg 22607, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Bomme
authors.affiliation: Argonne National Laboratory, Argonne, Illinois 60439, USA.|SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA.
authors.forename: M
authors.initials: M
authors.lastname: Bucher
authors.affiliation: Argonne National Laboratory, Argonne, Illinois 60439, USA.
authors.forename: G
authors.initials: G
authors.lastname: Doumy
authors.affiliation: Deutsches Elektronen-Synchrotron (DESY), Hamburg 22607, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Erk
authors.affiliation: SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA.
authors.forename: K R
authors.initials: KR
authors.lastname: Ferguson
authors.affiliation: SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA.
authors.forename: T
authors.initials: T
authors.lastname: Gorkhover
authors.affiliation: Argonne National Laboratory, Argonne, Illinois 60439, USA.
authors.forename: P J
authors.initials: PJ
authors.lastname: Ho
authors.affiliation: Argonne National Laboratory, Argonne, Illinois 60439, USA.
authors.forename: E P
authors.initials: EP
authors.lastname: Kanter
authors.affiliation: Argonne National Laboratory, Argonne, Illinois 60439, USA.
authors.forename: B
authors.initials: B
authors.lastname: Krässig
authors.affiliation: SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA.
authors.forename: J
authors.initials: J
authors.lastname: Krzywinski
authors.affiliation: SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA.
authors.forename: A A
authors.initials: AA
authors.lastname: Lutman
authors.affiliation: Argonne National Laboratory, Argonne, Illinois 60439, USA.
authors.forename: A M
authors.initials: AM
authors.lastname: March
authors.affiliation: Argonne National Laboratory, Argonne, Illinois 60439, USA.
authors.forename: D
authors.initials: D
authors.lastname: Moonshiram
authors.affiliation: SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA.|Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
authors.forename: D
authors.initials: D
authors.lastname: Ray
authors.affiliation: Argonne National Laboratory, Argonne, Illinois 60439, USA.
authors.forename: L
authors.initials: L
authors.lastname: Young
authors.affiliation: Argonne National Laboratory, Argonne, Illinois 60439, USA.
authors.forename: S T
authors.initials: ST
authors.lastname: Pratt
authors.affiliation: Argonne National Laboratory, Argonne, Illinois 60439, USA.
authors.forename: S H
authors.initials: SH
authors.lastname: Southworth