High-Pressure Diffraction and 4th Generation Sources
Malcolm I. McMahon
School of Physics and Centre for Science at Extreme Conditions, The University of Edinburgh, Edinburgh EH9 3JZ, UK
The last 15 years have seen an unprecedented growth in the number of detailed structural studies conducted at high pressure. In that time, new experimental methods, and the advent of 3rd generation light sources such as the ESRF, APS and Spring-8, have seen detailed structural refinements extended to above 200GPa, and the discovery of ever more complex structure types. In many cases, these structural studies have been accompanied by other x-ray based techniques, such as inelastic x-ray scattering, x-ray raman scattering and x-ray nuclear scattering, which have all been made possible by the use of 3rd generation sources.
The construction of 4th generation sources, such as the Cornell ERL, will offer ultra-high brilliance beams of hard x-rays that are only a few microns in diameter, and which will also have very low emittance, transverse coherence, and very short pulse lengths. In this talk I will illustrate current state-of-the-art x-ray diffraction and scattering studies at 2nd and 3rd generation sources, using some recent results on incommensurate Rb, Sc and S at high-pressure. I will then look to the kinds of new science that might be possible on such systems using the ERL.
