title: Two-step hard X-ray focusing combining Fresnel zone plate and single-bounce ellipsoidal capillary.
abstract: A two-step focusing set-up combining a Fresnel zone plate with an ellipsoidal capillary is presented. It is shown that, in addition to the anticipated gain in flux, the employment of the prefocusing micro-optic makes optimal use of the elliptical shape of the capillary by almost eliminating aberrations. A small cross section of the prefocused beam allows a tiny fraction of the capillary surface to be selected, thus reducing the influence of slope errors. An X-ray beam with a 15 keV energy was focused down to a spot size as small as 250 nm, demonstrating the best value that has been achieved up to now for single-bounce capillaries. The use of an ellipsoidal capillary as a micromirror under off-axis illumination by microfocusing optics may open up new opportunities in nanofocusing developments.
authors.affiliation: European Synchrotron Radiation Facility, 6 rue Jules Horowitz, 38043 Grenoble, France.
authors.forename: A
authors.initials: A
authors.lastname: Snigirev
authors.forename: A
authors.initials: A
authors.lastname: Bjeoumikhov
authors.forename: A
authors.initials: A
authors.lastname: Erko
authors.forename: I
authors.initials: I
authors.lastname: Snigireva
authors.forename: M
authors.initials: M
authors.lastname: Grigoriev
authors.forename: V
authors.initials: V
authors.lastname: Yunkin
authors.forename: M
authors.initials: M
authors.lastname: Erko
authors.forename: S
authors.initials: S
authors.lastname: Bjeoumikhova