Elettra-Sincrotrone Trieste S.C.p.A. website uses session cookies which are required for users to navigate appropriately and safely. Session cookies created by the Elettra-Sincrotrone Trieste S.C.p.A. website navigation do not affect users' privacy during their browsing experience on our website, as they do not entail processing their personal identification data. Session cookies are not permanently stored and indeed are cancelled when the connection to the Elettra-Sincrotrone Trieste S.C.p.A. website is terminated.
More info



The insertion device

The wiggler for the SAXS beamline consists of three 1.5 m long segments, each having 19 poles. The device can work with a minimum gap of 20 mm, which corresponds to K=20 at 2 GeV. The main parameters of the wiggler are:
·      Critical Energy 4.1 keV
·      Radiation Power 8.6 kW
·      Flux 3.5x1014 ph/s/mrad/0.1%BW (at 400 mA)

The wiggler radiation cone has a horizontal width of 9 mrad. From this the SAXS-beamline accepts vertically 0.3 mrad, and horizontally +/-0.5 mrad at a 1.25 mrad off-axis position. The resulting source size for 8 keV photons is 3.9 x 0.26 mm2 (horiz. x vert.).

The beamline optics

The optics common with the diffraction beamline consists of:
·      Carbon-Filter to reduce the power load on the first optical elements by a factor of 2
·      Beryllium windows to separate the beamline vacuum from the storage ring
·      Beam defining slit chamber before the SAXS monochromator
The SAXS beamline optics consists of:
·      A double-crystal monochromator
·      A baffle chamber after the monochromator is used as an adjustable straylight fenditure
·      A segmented toroidal mirror focuses the light in horizontal and vertical direction with a 1/2.5 magnification onto the SAXS-detector
·      An aperture slit reduces the straylight after the monochromator and the toroidal mirror
·      A guard slit defines the illuminated region on the sample

Scientific applications

Low Contrast Solution Scattering, Grazing Incidence Surface Diffraction, Micro-Spot Scanning, X-ray Fluorescence Analysis, Time-Resolved Studies > 11 µs and Simultaneously Performed Small- and Wide-Angle Measurements (SWAXS) on:

·      Gels and colloids
·      Liquid Crystals
·      (Bio) Polymers
·      Amorphous Materials
·      Muscles
·      Proteins
·      Metals, cements, oils
·      Quantum dots
·      and much more ...

Source characteristics

The photons are provided by a Wiggler (NdFeB Hybrid) with the following specifications:

Period: 140 mm
Number of full poles: 57
Gap: 20 mm
Bmax: 1.607 T
Critical Energy Ec: 4.27 eV   (at 2 GeV)
Power (9 mrad): 8.6 kW   (at 2 GeV, 400 mA)
effective source size FWHM: 3.9 x 0.26 mm2(HxV)   (at 2 GeV, 400 mA)



Double crystal monochromator:  18.4 m from source, Si (111) asym. cut, water cooled
Focussing mirror: 26.5 m from source, two segments, toroidal, Pt coated
Acceptance: 1 mrad/0.3 mrad (HxV)
Energy (3 selectable): 5.4, 8, 16 keV (0.077, 0.154, 0.23 nm)
Energy resolution deltaE/E: 0.7-2.5 x 10-3
Focal spot size FWHM: 1.2 x 0.6 mm2 (HxV)
Spot at Sample FWHM: < 1.4 x 1.8 mm2(HxV) (using slits or pinhole)
smallest possible spot: 10 µm
Flux at sample: 1 x 1013 ph s-1 (2 GeV, 400 mA, 8 keV)
Flux density at sample: 1 x 1012  ph s-1 mm-2  (2 GeV, 400 mA, 8 keV)

Experimental resolution

Small angle:
Real space: 1-140 nm 

Wide angle:
0.1- 0.9 nm 


Accessible SAXS and WAXS range

Small angle:

Real space: 1-140 nm (8 keV)
                     1-63 nm (16 keV)

Wide angle:

angular region from 17 - 85o  (2Theta)


Simultaneous SAXS- and WAXS-measurements can be performed using a Pilatus3 1M detector for the SAXS signal, and a Pilatus 100k detector for the WAXS-range.

For transmission experiments, also a specially designed vacuum chamber (SWAXS-nose, see Annual Report of 1996/97, p. 32) can be used which allows to use both scattering areas below (for SAXS) and above (for WAXS) the direct beam, respectively. The overall length of the SWAXS-nose in horizontal direction, measured from the sample position, is 512 mm and the fixed sample to WAXS-detector distance is 324 mm. Therefore, at the shortest SAXS camera-length an overlap in the d-spacings covered by the SAXS- and WAXS-detectors, respectively, is possible: then, the common regime lies around 9 Å (at 8 keV, using for WAXS the 2Theta = 9.4 - 27.6o range).

Last Updated on Monday, 29 April 2019 15:20