RHEED-TRAXS

RHEED-TRAXS (Reflection High Energy Electron Diffraction - Total-Reflection-Angle X-Ray Spectroscopy) is a technique for monitoring the chemical composition of crystals. RHEED-TRAXS analyzes X-Ray spectral lines emitted from a crystal as a result of electrons from a RHEED gun colliding with the surface.

RHEED-TRAXS is preferential to X-Ray Microanalysis (XMA) because the incidence angle of the electrons on the surface is very small, typically less than 5°. As a result, the electrons do not penetrate deeply into the crystal, meaning the X-Ray emission is restricted to the top of the crystal.

The experimental setup is fairly simple. Electrons are fired onto a sample causing X-Rays to be excited. These X-Rays are then detected using a Si(Li) crystal placed behind Beryllium windows, used to maintain vacuum.

Sources

Hasegawa, Ino, Yamamoto, Daimon - Chemical Analysis of Surfaces by Total-Reflection-Angle X-Ray Spectroscopy in RHEED Experiments (RHEED-TRAXS)

--Jason Francis 00:09, 2005 Jan 19 (UTC)