Beam conditioning optics
Elliptically or parabolically bent multilayer reflectors can monochromatise a divergent X-ray and focus respectively collimate (parallelise) it at the same time. Thus a small line source can be reproduced as a line or collimated in a parallel beam with a rectangular cross section.
Typical parameters:
| Spectral lines: | Cr, Co, Cu, Ga, Mo, Ag |
| Typical peak reflectivity: | R > 70% (depending on angle and energy) |
| Monochromaticity: | Kα1+Kα2 or Kβ |
| Divergency (parabolic optic): | typically ΔΦ < 0.03° |
| (with a generator of 40µm) | |
| Typical parallel beam width: | 1.0mm (Mo-K, L = 100mm) |
| 1.5mm (Cu-K, L = 60mm) | |
| Typical focus dimension: | < 30µm ... 500µm |
| Typical focal distance: | 60 - 100mm (focal point/focus to reflection centre) |
| Focal distance relation: | f1:f2 ~ 1:1 .. 1:5 (elliptic reflector) |
| others on request |
2-dimensional beam conditioning optics:
Two bent optics at right angles to one another (ASTIX geometry) make it possible to focus a dimple spring in one point (ASTIX-f) or to collimate it to a beam with a square cross section (ASTIX-c). A hybrid optic allows for a combination between focusing in one direction and collimating in the other (ASTIX-h).
1-dimensional elliptic optic:
An optic which is bent elliptically in one dimension focuses the beam of a divergent dimple spring or line source in a line. The distances between source, reflector and focus can be set user-defined and cause a variable magnification or diminution of the focus.
2-dimensional elliptic optic:
Two elliptic optics which are at right angles to one another focus the divergent beam of a dimple spring in one point (ASTIX-f). Its dimension can be regulated by choosing the distance between source, reflector and focus. Typical diameters are in the range of < 30µm and 500µm.
2-dimensional parabolic optic:
Two parabolic optics which are at right angles to one another (ASTIX-c) collimate the divergent beam of a dimple spring to a parallel beam with square cross section (typical lateral length: 1.0 - 2.2mm) or focus a parallel beam in one point.