Plane Mirror

The plane mirror is used for the high pressure experiments.

Toroidal mirror

photograph of the toroidal mirror (200kB)

The toroidal mirror is used for the time resolved experiments for either white beam (Laue) measurements or monochromatic experiments together with the double crystal monochromator. Its shape is determined by a strong bending perpendicular to the x-ray beam to focuss in the horizontal direction and a light bending along the beam path to focuss the vertical direction. The focal spot at the sample position is thus ideally 0.18 x 0.20 mm, but degrades with a high heat load on the optical elements.

The parameters of both mirrors are summarized in the table below:
 

- mirror 1 mirror 2
shape cylindrical (toroidal)  plane (parabolic)
dimensions : L x W x H(mm3)   1000 x 130 x 100  1200 x 100 x 50
material  SiC on a graphite body  Si(single-crystal)
sagittal radius 64.53 -
coating Pt Pt
surface roughness (Å; rms) 1.8 1
incidence angles (mrad) 2.335 1.25 - 5.0
energy range (keV) 5 - 39 5 - 55
distance source-mirror (m) 28.1; 29.7; 31.3 33.9; 35.5; 37.1
mirror-focus distance(m)  26.8 7.0
demagnification M 0.85 - 0.95 0.2
slope error (µrad; rms) 9.0 (4.21 over 380 mm in the centre) 6.0
gravity sag (km) 4.7 6.9
bending range (km) 1.8 - 4.7  1.5 - 6.9