Optical elements
distance from source
First mirror
Rh strip
~=29.7 m
Monochromator
pseudo channel-cut type
~=31.4 m
Second mirror
two strips Si and Rh
~=34.6 m
focusing type vertically collimating dynamically sagital focusing vertically focusing
horizontal acceptance
spectral range
2 mrad
6.0-35 KeV
flux at sample 1012ph/s
(beam current 0.2 A)
nominal beam
size at
B1 B2 B3
(H x V) ~=0.1 x 0.1 mm2 ~=0.1 x 0.1 mm2 ~=0.1 x 0.1 mm2


 

 As in the case of branch A, the optics accept the 2 mrad horizontal radiation and produce a small focal spot at different positions (B1, B2, and B3) in the experimental hutch B. The first mirror is collimator and is located before the monochromator beamstream. The figure shows schematically the chosen design. The horizontal focusing is achieved, as in the case of branch A, by the second monochromator crystal through a sagittal cylindrical bending. For focusing in the meridional plane a cylindrical bent mirror is used. The vacuum of the main components is separated by fixed Be Windows. The main function of the first mirror is to reject the higher order harmonics and produce a non dispersive optical setting. Since a Si strips coating is used, in normal operation, the glancing angle is ~ 2.5 mrad, which corresponds to a cut-off energy of 26.8 keV. A pseudo channel-cut type monochromator is used. Two Si(111) crystals are used and they rotate by a single table, in the (+n,-n) configuration. Contrary to the case of Branch A the beam is moved upward in order to gain more free space at the sample position in the experimental hatch B. The Si(111) Darwin width meets the bandwidth necessities for resonant anomalous scattering measurements. A post-monochromator channel-cut type is foreseen for High Energy X-ray Photoelectron Spectroscopy. Additional harmonics rejection is obtained by angular detunning. The first crystal is flat, while the second is curved in the horizontal plane in order to focus the beam at different positions B1, B2 and B3 (see figure). 

 Branch B

Schematic representation of beam path for the configuration of Branch B. Dimensions are given in millimeters.