The slit box is located after the monochromatic beam attenuators and bolted to the experimental table. It is comprised of two pairs of horizontal and vertical slits separated by a gap of 200 mm. This first pair of slits define the beam size and the second pair clean any scatter. The JJ-Xray slits are made of Tungsten carbide (type 6 UF), are 2 mm thick and the edge is cut with a 2 degrees angle like a knife blade. After the slits is a thin-foil diode (i0) for slit size calibration and quick realignments. A fast and reliable milli-second piezo shutter syncronised with the phi axis movement via MUSST unit follows the slits. Another thin-foil diode (i1) follows the shutter to ensure it opens correctly. The slit box has been prealigned manually to have beam going through two holes of 0.5 mm at the entrance and the exit of the box.


SlitBox Picture


The fine alignement of the slits is then done by using the horizontal (t1h and t2h) and vertical(t1v and t2v) stages which have +/- 7mm translation range (stepper motor 0.15 micron per half step). The size of the beam is defined by changing the gap of the slits horizontally (s1h and s2h) and vertically (s1v and s2v). The second pair is added to cut off side scattering coming from the first set of slits. The maximum aperture is 6 mm by 6 mm (stepper motor 0.4 micron per half step).


SlitBox Schema