X-ray Diffractometry

Optics for X-Ray Diffraction

Incoatec offers different types of optics for X-ray diffraction devices. Nowadays the most widespread optics for XRD are the so-called "Göbel Mirrors". Göbel Mirrors (GM) convert the X-ray beam coming from an X-ray tube into a parallel beam and additionally monochromatizes it. The mirrors consist of multilayers with laterally graded thickness, deposited extremely accurately onto a parabolic surface.

• More than 10⁹ photons/sec with sealed tubes
• Divergence of 0.5 mrad, other divergences if required
• For Cr, Co, Cu, Mo radiation
• Optics with various lengths, focal distances and divergences
• Kirkpatrick-Baez configurations
• Customer-specific models

X-ray instruments equipped with Göbel Mirrors show dramatically improved performances in various types of measurements compared with instruments without this mirror. A typical application for GM's is the X-ray Reflectometry (XRR). The intensity achieved with a GM is more than 10 times higher. Better data in shorter times! It is also possible to carry out measurements in X-ray Reflectometry over 9 orders of magnitude with a sealed tube X-ray source. These results can usually only be surpassed by synchrotron X-ray sources.

A significant intensity gain was also achieved using our X-ray Göbel mirrors in measurements of High Resolution Diffractometry (HRXRD). This was made possible by the development of the so-called 3rd generation GMs. These 3rd Gen GM's consist of an ultra-precise prepolished parabolical form (with slope errors down to 1 arcsec rms) with an ultra-precise multilayer coating (pat. US 6226349). The intensity achieved by directing a beam from the 3rd Gen GM into channel-cut crystals was 16 times higher compared to a set-up without a GM.

3rd Generation for highest resolution:

• optics with slope errors of 1 arcsec
• lowest divergence and best parallel beam
• best monochromatization

Together with the standard parallel beam Göbel Mirror, Incoatec also produces both convergent beam as well as divergent beam Göbel Mirrors. For some applications, for example in powder diffractometry, a parallel beam is not always the best choice. Better results are obtained by a slightly divergent Göbel Mirror that maximizes the intensity and has a larger sample footprint.

Our product range includes optics for various types of tubes. Customer-specific mirrors beyond these data can be produced as well.