Picosecond diffraction at the ESRF: How far have we come and where are we going?

Abstract

The realization of solution phase pump-probe diffraction experiments on beamline ID09B is described. The pink beam from a low-K in-vacuum undulator is used to study the structural dynamics of small molecules in solution to 100 picosecond time resolution and at atomic resolution. The X-ray chopper and the associated timing modes of the synchrotron are described. The dissociation of molecular iodine in liquid CCl4 is studied by single pulse diffraction. The data probe not only the iodine structures but also the solvent structure as the latter is thermally excited by the flow of energy from recombining iodine atoms. The low-q part of the diffraction spectra is a sensitive probe of the hydrodynamics of the solvent as a function of time. © 2007 American Institute of Physics.