Specifications

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