Nanoscale dynamics of liquids: S(Q,ω) with 0.8 meV resolution using x-rays

We describe a new instrument for measuring the dynamic structure factor of liquids, S(Q,ω) , at the RIKEN SPring-8 Center in Japan using inelastic x-ray scattering (IXS) (see https://arxiv.org/abs/1504.01098). A long, 15m, insertion device provides unprecedented x-ray intensity, making practical experiments possible with sub-meV resolution at sub nm^-1 momentum transfers. This allows new insight into the mesoscale crossover regions between hydrodynamic and atomistic behavior of liquids. The performance will be illustrated with examples, including new results from liquid water [Ishikawa & Baron, submitted] and liquid iron [Baron, Inui, Ishikawa, et al, work in progress], demonstrating the range of the instrument and its applicability to even rather difficult experiments.