High energy synchrotron radiation. A new probe for condensed matter research

The absorption of 150 keV synchrotron radiation in matter is weak and, as normally done with neutrons, bulk properties are studied in large samples. However, the k-space resolution obtained with a Triple Crystal Diffractometer (TCD) for high energy synchrotron radiation is about one order of magnitude better than in high resolution neutron diffraction. The technique has been applied to measure the structure factor S(Q) of amorphous solids up to momentum transfers of the order of 32 Å-1, to study the intermediate range Ortho-II ordering in large, high quality YBa2Cu3O6.5 single crystals and for investigations of the defect scattering from annealed Czochralski grown silicon crystals. Magnetic superlattice reflections have been measured in MnF2 demonstrating the potential of the technique for high resolution studies of ground state bulk antiferromagnetism. Recently the question of two length scales in the critical scattering at the 100 K phase transition in SrTiO3 was studied. At the PETRA storage ring, which serves as an accumulator for the HERA electron-proton-ring at DESY and which can be operated up to electron energies of 12 GeV, an undulator beam line is currently under construction and should be available in summer 1995. It opens up exciting new research opportunities for photon energies from about 20 to 150 keV