The F3 station is a versatile bend-magnet station that can accommodate a variety of experimental capabilities. It has a double-crystal Si (111) as a standard monochromator with a sagittal focusing second crystal which focuses about 3 mrad of bending magnet radiation, tunable from 6 to 18 keV. A vertically focusing mirror will be installed downstream of the monochromator to provide a doubly-focused beam at the station. Alternatively, four sets of unfocused multilayers can be used as the monochromator, providing wide-bandpass radiation at 0.22%, 2%, 5%, or 10% with a tunable energy range of 5-11 keV. Considerable efforts are currently devoted to novel optics development and characterization at the station, especially in the area of high-resolution and other special multilayers.
Two standard experimental setups are available at F3. The first is a conventional small 4-circle diffractometer with an analyzer th-2th stage for high resolution diffraction, x-ray reflectivity, and diffuse scattering studies. Typical samples include semiconductor and organic thin-films, small molecule crystals, nanofabricated or self-organized lateral quantum dot structures. This setup also is suitable for x-ray topographic studies, x-ray imaging, and small / wide-angle scattering experiments. An x-ray fluorescence detector can be set up to monitor fluorescence signals from the specimen for resonant / anomalous diffraction, surface scattering, and x-ray standing wave experiments. An x-ray polarimeter (shared with C-line) may be mounted on the 2-th arm for polarization analysis of a diffracted beam.
The second setup at F3 is a special 5-circle kappa diffractometer with a Quantum-4 CCD area detector (or Fuji image plates) and a complete shutter-collimator-video camera setup for oscillation crystallography data collection. The special 5-circle diffractometer along with a special version of CCD control software is designed for direct phase measurements of Bragg reflections in oscillation crystallography using a reference-beam diffraction phasing technique. The diffractometer geometry can also be arranged as a standard oscillation camera with a single horizontal rotation axis, controlled through standard MacCHESS oscillation software. Other experiments using this setup include studies of disorders in protein crystals, radiation damage control in protein crystallography, and SAD phasing with intrinsic sulfur anomalous signals at <6 keV.
| F3 Station Summary | |
| Source: | e+s, Hard bend magnet HB7E, 6 mrad (horizontal) into F3 |
| Source size: | FWHM (horizontal) = 3.63 mm, FWHM (vertical) = 1.06 mm |
| Distance to source: | 21.6 m to center of hutch |
| Be Windows: | 0.040 inch to F3 hutch |
| Cave slit sizes: | 0 to 80 mm (horizontal), 0 to 5 mm (vertical) |
| Monochromators: | Double-bounce downward, offset 25 -110 mm |
|
|
|||||
| Crystals | Sag. Focus. | Energy (keV) | λ | λ/2 | λ/3 |
| Si (111) | Yes | 6 - 20 | 1.3 | 0.008 | 0.093 |
| Si (111) | No | 6 - 20 | 1.3 | 0.008 | 0.093 |
| 2% Multilayers | No | 6 - 11 | 200 | ||
| 0.22% Multilayers | No | 6 - 11 | 22 | ||
| Monochromatic Mirrors | |||
| Type | Length | Vertical Focus | E*θ°(keV-mrad) |
| Rh coated Si (available soon) |
600 mm | Yes | 67.0 |
| Typical Experiments | |
| Type | Equipment Setup |
| High Res. Scattering | Small Huber 6-circle diffractometer |
| EXAFS | Optical Table |
| Near-edge diffraction | |
| Oscillation Crystallography | |
| Scanning X-ray Fluorescence Spectroscopy | Optical Table |
