BM05 Users Guide

The BM05 beamline serves as a test and development station for X-ray optical elements, beam characterisation (coherence, polarisation…), and instrumentation R&D in general. The beamline is available for internal development and for proprietary research.

This beamline is unique in terms of flexibility. It offers the specific characteristics:

  • Coverage of a large energy-range, from 6 keV to 60 keV using 2 monochromators
  • Variable energy resolution: ΔE/E< 10-4 when using Si(111) crystals, ΔE/E~ 10-2 when using multilayers.
  • High monochromaticity by combining Bragg reflection on crystals and multilayers (harmonic rejection <10-5).
  • Various customizable stations located at ~28 m, ~40 m and ~55 m where either white beam or monochromatic beam can be delivered.

Scientific applications

Most experiments performed at BM5 are related to Methods & Instrumentations.

1. X-Ray Optics

  • Characterization of optical elements (reflectometry and diffractometry): mirrors, multilayers, single crystals
  • Performance tests of microfocusing optical elements (mirror benders)
  • Testing of optical devices and schemes based on Fresnel and Bragg-Fresnel lenses, refractive and diffractive lenses, waveguides, Laue-Bragg monochromator…

2. Metrology instrumentation

  • Coherent and incoherent mirror and multilayer metrology
  • Interferometry using crystals, gratings…

3. Other Instrumentation Developments

  • Detector tests: spatial resolution and performance of 2D detectors of various kinds
  • Time-Resolved Setups: Choppers, surface-acoustic wave devices.

4. Preparation of new beamlines (feasibility, performance evaluation, first experience)

  • High energy beam conditioning: Laue-Bragg monochromator, curved and graded multilayers
  • Dispersive EXAFS: real and reciprocal space focusing
  • Diffuse scattering: ultra-high resolution SAXS, study of point defects
  • Topography (absorption and phase contrast): study of crystal defects
  • Computed tomography (medium resolution)
  • Microfluorescence: experiments using hybrid optics

5. Other Experiments

  • Reciprocal space mapping: short-range strains, study of quantum dots and wires
  • Microdiffraction: study of grain size, strain, mosaic structure
  • Two and three-axis high resolution diffractometry: measurements of strains
  • Radiation studies (white beam)

Techniques Available

X-ray Reflectometry and Diffractometry

  • A horizontal diffractometer, work horse of the beamline, allows multiple configurations using up to 3-axis for reciprocal space mapping. It can take sample environments of up to 100 kg weight. X-ray diffractometry with micrometer spatial resolution can also be performed using the FreLon camera. Additional optical elements can be installed on any of the 3-axes or on a table located at about 1 metre in front of the diffractometer, so that this instrument also serves as test station for various kinds of optical elements. Notice also that white beam can also be used in this hutch.
  • A two-axis vertical reflectometer (2θ up to 130°) is also available. It is useful for the study of thin films on small samples or when diffraction at high angles is needed (in this case not affected by the beam polarization). While the standard configuration uses an unfocused beam, the flux can be maximised by focusing the beam in the horizontal direction (sagittal crystal monochromator for energies up to ~ 30 keV).
  • A five-circle commercial diffractometer (3 circles for sample orientation, 2 circles for detectors) is available to address the high-throughput multi-characterisation R&D rapid-access needs of the micro- and nano-electronics industry. The instrument was financed by the French IRT Nanoelec programme via a collaboration between CEA-LETI and ESRF. The available  X-ray characterisation techniques include in-plane and out-of-plane diffraction, both in reflection and transmission, anomalous diffraction, CD-SAXS, PDF measurements on amorphous thin layers, fluorescence, reflectivity and diffraction imaging (white and monochromatic x-ray topography, rocking curve imaging). Different detectors are available including 0D scintillation APD detectors and 2D Pixirad FreLon or a PCO cameras. It is installed in the second hutch at a mean distance from the source of 57 m, so that the beam has a maximum size of 120 mm x 6 mm in the monochromatic case or of 165 mm x 7 mm in the case of white beam (FWHM). The setup is also used to measure diffuse scattering on polished surfaces or to qualify the uniformity response of detectors. A bent multilayer bending mounted upstream (optics table) may be used to concentrate the x-ray beam in the horizontall direction down to 30 micrometers.

Complementary Information