title: Wavefield characterization of nearly diffraction-limited focused hard x-ray beam with size less than 10 nm.
abstract: In situ wavefront compensation is a promising method to realize a focus size of only a few nanometers for x-ray beams. However, precise compensation requires evaluation of the wavefront with an accuracy much shorter than the wavelength. Here, we characterized a one-dimensionally focused beam with a width of 7 nm at 20 keV using a multilayer mirror. We demonstrate that the wavefront can be determined precisely from multiple intensity profiles measured around the beamwaist. We compare the phase profiles recovered from intensity profiles measured under the same mirror condition but with three different aperture sizes and find that the accuracy of phase retrieval is as small as λ∕12.
authors.affiliation: Department of Precision Science and Technology, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871, Japan. kimura@up.prec.eng.osaka-u.ac.jp
authors.forename: Takashi
authors.initials: T
authors.lastname: Kimura
authors.forename: Hidekazu
authors.initials: H
authors.lastname: Mimura
authors.forename: Soichiro
authors.initials: S
authors.lastname: Handa
authors.forename: Hirokatsu
authors.initials: H
authors.lastname: Yumoto
authors.forename: Hikaru
authors.initials: H
authors.lastname: Yokoyama
authors.forename: Shota
authors.initials: S
authors.lastname: Imai
authors.forename: Satoshi
authors.initials: S
authors.lastname: Matsuyama
authors.forename: Yasuhisa
authors.initials: Y
authors.lastname: Sano
authors.forename: Kenji
authors.initials: K
authors.lastname: Tamasaku
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Komura
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Nishino
authors.forename: Makina
authors.initials: M
authors.lastname: Yabashi
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Ishikawa
authors.forename: Kazuto
authors.initials: K
authors.lastname: Yamauchi