High resolution inelastic X-ray scattering from thermal collective excitations

¹ Institut de Minéralogie et de Physique des Milieux Condensés (IMPMC), CNRS UMR 7590, Université Pierre et Marie Curie - Paris 6, case 115, 4 place Jussieu, 75252 Paris Cedex 05, France
² European Synchrotron Radiation Facility, BP. 220, 38043 Grenoble Cedex, France

Abstract

In this lecture we will introduce the general characteristics of non-resonant X-ray inelastic scattering, in particular its scattering and absorption cross-section as well as its kinematic conditions. We will then present how it is possible to achieve meV energy resolution with keV X-rays, hence performing light inelastic scattering of thermal excitations with a wavelength of the order of inter-atomic spacing in liquids and solids. We will describe the perfect crystal monochromator back-scattering experimental set-up and the resulting instrumental function in energy and momentum space. We will then discuss the consequence of the above mentioned experimental characteristics, in particular for the application of the technique to phonon dispersion measurements in crystals, in comparison with triple axes inelastic neutron scattering and Raman experiments.