Small Angle X-ray Scattering has become a well known standard method to study the structure of various objects in the spatial range from 1 to 1000 nm, and therefore instruments capable to perform such experiments are installed at most of the synchrotron research centers. The high-flux SAXS beamline at ELETTRA is mainly intended for time-resolved studies on fast structural transitions in the sub-millisecond time region in solutions and partly ordered systems with a SAXS-resolution of 1 to 140 nm in real-space.
The photon source is the 57-pole wiggler whose beam is shared and used simultaneously with a Macromolecular Crystallography beamline. From the very intense wiggler radiation, the SAXS-Beamline accepts 3 discrete energies, namely 5.4, 8 and 16 keV (0.077, 0.154, 0.23 nm). The beamline optics consists of a flat, asymmetric-cut double crystal monochromator and a double focusing toroidal mirror.
A versatile SAXS experimental station has been set-up, and an additional wide-angle X-ray scattering (WAXS) detector monitors simultaneously diffraction patterns in the range from 0.1 to 0.9 nm. The sample station is mounted movable onto an optical table for optimising the sample detector distance with respect to SAXS resolution and sample size.
Besides the foreseen sample surrounding, users have the possibility to install their own specialised sample equipment. In the design phase, besides technical boundary conditions, user friendliness and reliability have been considered as important criteria.
Furthermore, using 5.4 and 16 keV energies, the beamline is widely applicable also to very thin, e.g. single muscle fibers, and optically thick (high Z) specimen, as often used in e.g., material science and solid state physics.
(click to enlarge)
| Wiggler | NdFeB Hybrid |
|---|---|
| Period | 140 mm |
| No. full poles | 57 |
| Gap | 20 mm |
| Bmax | 1.607 T |
| Critical Energy Ec | 4.27 keV |
| Power (9 mrad) | 8.6 kW |
| Effective source size FWHM | 3.9 x 0.26 mm2(HxV) |
| Optical elements | Double crystal monochromator:Si (111) asym. cut, water cooled. | Mirror:two-segment,toroidal, Pt coated. |
|---|---|---|
| Distance from source | 18.4 m | 26.5 m |
| Acceptance | 1 mrad/0.3 mrad (HxV) |
|---|---|
| Focal spot size FWHM | 1.2 x 0.6 mm2 (HxV) |
| Energy (3 selectable) | 5.4, 8, 16 keV (0.077, 0.154, 0.23 nm) |
|---|---|
| Energy resolution DE/E | 0.7-2.5 x 10-3 |
| Photon flux | 5 x 1012 ph s-1(2 GeV, 200 mA, 8 keV) |
| Spot at Sample FWHM | < 5.4 x 1.8 mm2(HxV) |
| Resolution in real space | 1-140 nm (small-angle), 0.1- 0.9 nm (wide-angle) |
More information can be found at:
Heinz AMENITSCH
email heinz.amenitsch@elettra.trieste.it
tel: + 39 040 375 8363/8044
fax: + 39 040 9380 902
Peter LAGGNER
email peter.laggner@oeaw.ac.at
tel: + 43 316 4120 302
fax: + 43 316 4120 390
Sigrid BERNSTORFF
email sigrid.bernstorff@elettra.trieste.it
tel: + 39 040 375 8572
fax: + 39 040 9380 902