Speaker: Sine Larsen, Department of Chemistry, University of Copenhagen, Denmark.

Date: 2010-02-26

Time: 14:15

Place: Chemistry department, K:B, Getingevägen 60, Lund

Abstract: Biological and soft matter samples have a lot of properties in common, they are complex, difficult to handle and weak scatters of X-rays. One way of improving the signal to noise ratio of the scattering signal is to use the small well focused very intense X-ray beams that have become available at the 3rd generation synchrotrons. The continuous exponential growth of protein structures that have been determined based on data measured with synchrotron radiation makes it fair to state that synchrotron radiation has revolutionized macromolecular crystallography. Similar achievements have been observed for Soft Matter research by the use of synchrotron radiation. The success in the use of the intense X-rays from synchrotrons on biological and soft matter samples is even more remarkable if one considers the rate by which the samples are destroyed in the intense synchrotron beams. Radiation damage imposes severe restrictions on the use of synchrotron radiation and the effects can be minimized by cooling the sample and optimization of the experimental set-up at the beamlines for macromolecular crystallography.  Neutrons do not exert the same negative effect on biological and soft matter samples another advantage of using neutrons instead of photons is that they open the possibility to investigate the position and dynamics of hydrogen atoms. Examples will be presented on how the complementarities of X-rays and neutrons are exploited increasingly in investigations of biological and soft matter samples and how this has stimulated scientific partnerships that involve synchrotrons and neutron sources.