The slits system on the D2am Material sciences goniometer

Incoming beam slits

After the 3 slits system described in the Overview of the beamline Optic, the slits (s* = s4, s5 ,s6 and s7) system are manufactured by Riso: they have a 40*40mm aperture defined by four independent lips. All those slits can be moved lip by lip : slit up (su*), slit down (sd*), slit front (sf*) and slit back (sb*), or with pseudo-motors gap (hg*, vg*) and offset (ho*,vo*). s4 is installed on the goniometer about 50cm before the sample, still under secondary vacuum. It is used to define the beam size in the horizontal (hg4) and vertical (vg4) directions. A pre-alignment of the goniometer center on the beam should bring their offsets (ho4 and vo4) close to zero.

Receiving slits on the detector arm.

The detector arm can be equipped with 1 or 2 slits containing both horizontal and vertical gap (hg6,vg6 and hg7,vg7).