title: A beam branching method for timing and spectral characterization of hard X-ray free-electron lasers.
abstract: We report a method for achieving advanced photon diagnostics of x-ray free-electron lasers (XFELs) under a quasi-noninvasive condition by using a beam-splitting scheme. Here, we used a transmission grating to generate multiple branches of x-ray beams. One of the two primary diffracted branches (+1st-order) is utilized for spectral measurement in a dispersive scheme, while the other (-1st-order) is dedicated for arrival timing diagnostics between the XFEL and the optical laser pulses. The transmitted x-ray beam (0th-order) is guided to an experimental station. To confirm the validity of this timing-monitoring scheme, we measured the correlation between the arrival timings of the -1st and 0th branches. The observed error was as small as 7.0 fs in root-mean-square. Our result showed the applicability of the beam branching scheme to advanced photon diagnostics, which will further enhance experimental capabilities of XFEL.
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Katayama
authors.affiliation: RIKEN SPring-8 Center , 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan.
authors.forename: Shigeki
authors.initials: S
authors.lastname: Owada
authors.forename: Tadashi
authors.initials: T
authors.lastname: Togashi
authors.affiliation: RIKEN SPring-8 Center , 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan.
authors.forename: Kanade
authors.initials: K
authors.lastname: Ogawa
authors.affiliation: Paul Scherrer Institut , CH-5232 Villigen, Switzerland.
authors.forename: Petri
authors.initials: P
authors.lastname: Karvinen
authors.affiliation: Paul Scherrer Institut , CH-5232 Villigen, Switzerland.
authors.forename: Ismo
authors.initials: I
authors.lastname: Vartiainen
authors.affiliation: Paul Scherrer Institut , CH-5232 Villigen, Switzerland.
authors.forename: Anni
authors.initials: A
authors.lastname: Eronen
authors.affiliation: Paul Scherrer Institut , CH-5232 Villigen, Switzerland.
authors.forename: Christian
authors.initials: C
authors.lastname: David
authors.affiliation: RIKEN SPring-8 Center , 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Sato
authors.forename: Kyo
authors.initials: K
authors.lastname: Nakajima
authors.forename: Yasumasa
authors.initials: Y
authors.lastname: Joti
authors.affiliation: Japan Synchrotron Radiation Research Institute , 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198, Japan.
authors.forename: Hirokatsu
authors.initials: H
authors.lastname: Yumoto
authors.affiliation: Japan Synchrotron Radiation Research Institute , 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198, Japan.
authors.forename: Haruhiko
authors.initials: H
authors.lastname: Ohashi
authors.affiliation: RIKEN SPring-8 Center , 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan.
authors.forename: Makina
authors.initials: M
authors.lastname: Yabashi