Slits box

The slit blue box is located at beginning of experimental table. The JJ X-rays based slits have two pairs (horizontal and vertical) of blades, each with a Si-crystal layer, separated by 20 cm. They are made of tungsten carbide and their edge is cut with 6° angle. Just after the slit 1 is located a pinhole holder which allow to put in and out of the beam 100 µm diameter pinhole.

The alignment of the slits can be done in spec EXP by moving either their apertures (example: s1va is for vertical aperture/gap of slit 1) or their offsets (example: s2ht is for horizontal transaltion of slit 2). This can be done (with a test image taken at each movement) in a easy way in BsxCuBE tab Beamline (if logged as expert).

Slits 1 and 2 in slitbox are used for beam cleanning. The beam defining slit "sm" are placed at beginning of experimental hutch just after fast shutter and can be moved in the same way as slit 1 and 2 (i.e. via spec or BsxCuBE). They don't have Si sandwich layer.

Pinhole motors in spec EXP are piny and pinz. To move pinhole in/out the beam use piny and adjust pinz if necessary. Usually pinhole OUT corresponds to piny = -1.84 and pinhole IN to piny = +2.47 (yes, the hole is in the middle of a disk with 3 mm radius), pinz = -0.59 for both.

Guard slits define the illuminated spot on the sample, usually ~ 0.5 mm x 0.5 mm, resulting to ~ 0.2 mm by 0.2 mm beam on the detector plane. With the pinhole, illuminated sample area is smaller than 100 µm by 100 µm.