X-Ray Radiography
X-ray light can be used to see things that cannot be seen with the naked eye, for example whether a bone in your arm is broken or whether dangerous objects have been hidden in your luggage. You can even distinguish between different materials, as aluminum, for example, transmits much more X-ray light than copper. We use this X-ray radiography to analyze the concentration distribution in liquid and solidified materials in order to measure the movement of particles in the melt and the formation of crystals during solidification. By recording when and where the composition in the melt changes, the processes can be measured very precisely.
Where there are differences in composition, there are usually also differences in density. These differences in density can lead to flows due to buoyancy, which distort the measurements. For this reason, facilities have been developed to carry out selected experiments in zero gravity. This is how we obtain reference data during a parabolic flight or a rocket experiment.
The Institute of Materials Physics in Space has several specialized X-ray radiography facilities, which differ in the available detectors, the installation space and the power of the microfocus X-ray sources.