High-flux hard X-ray microbeam using a single-bounce capillary with doubly focused undulator beam
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{sup 13} photons s{sup -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{sup 12} photons s{sup -1}) and smaller spot sizes ({le}10 {micro}m FWHM in both directions) for a photon flux density of 4.2 x 10{sup 10} photons s{sup -1} {micro}m{sup -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{sup -2}. Micro-XANES experiments are also feasible using this combined optical arrangement.
- Research Organization:
- Argonne National Lab. (ANL), Argonne, IL (United States)
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 1005443
- Journal Information:
- J. Synchrotron Rad., Vol. 16, Issue (1) ; 01, 2009; ISSN 0909-0495
- Country of Publication:
- United States
- Language:
- ENGLISH
Similar Records
Optical design of the short pulse x-ray imaging and microscopy time-angle correlated diffraction beamline at the Advanced Photon Source
Beamline X29: A Novel Undulator Source for X-ray Crystallography