High-flux hard X-ray microbeam using a single-bounce capillary with doubly focused undulator beam
- 18 December 2008
- journal article
- research article
- Published by International Union of Crystallography (IUCr) in Journal of Synchrotron Radiation
- Vol. 16 (1), 76-82
- https://doi.org/10.1107/S0909049508039782
Abstract
A pre-focused X-ray beam at 12 keV and 9 keV has been used to illuminate a single-bounce capillary in order to generate a high-flux X-ray microbeam. The BioCAT undulator X-ray beamline 18ID at the Advanced Photon Source was used to generate the pre-focused beam containing 1.2 x 10(13) photons s(-1) using a sagittal-focusing double-crystal monochromator and a bimorph mirror. The capillary entrance was aligned with the focal point of the pre-focused beam in order to accept the full flux of the undulator beam. Two alignment configurations were tested: (i) where the center of the capillary was aligned with the pre-focused beam (;in-line') and (ii) where one side of the capillary was aligned with the beam (;off-line'). The latter arrangement delivered more flux (3.3 x 10(12) photons s(-1)) and smaller spot sizes (< or =10 microm FWHM in both directions) for a photon flux density of 4.2 x 10(10) photons s(-1) microm(-2). The combination of the beamline main optics with a large-working-distance (approximately 24 mm) capillary used in this experiment makes it suitable for many microprobe fluorescence applications that require a micrometer-size X-ray beam and high flux density. These features are advantageous for biological samples, where typical metal concentrations are in the range of a few ng cm(-2). Micro-XANES experiments are also feasible using this combined optical arrangement.Keywords
This publication has 5 references indexed in Scilit:
- Submicrometer hard X-ray focusing using a single-bounce ellipsoidal capillary combined with a Fresnel zone plateJournal of Synchrotron Radiation, 2007
- Single-bounce monocapillaries for focusing synchrotron radiation: modeling, measurements and theoretical limitsJournal of Synchrotron Radiation, 2005
- The BioCAT undulator beamline 18ID: a facility for biological non-crystalline diffraction and X-ray absorption spectroscopy at the Advanced Photon SourceJournal of Synchrotron Radiation, 2004
- Low-Angle Synchrotron Radiation Diffraction with Glass-Capillary OpticsJournal of Synchrotron Radiation, 1996
- Formation of Optical Images by X-RaysJournal of the Optical Society of America, 1948