Regensburg 2007 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 10: INTERNAL SYMPOSIUM Scattering Experiments I

CPP 10.6: Hauptvortrag

Dienstag, 27. März 2007, 11:15–11:45, H37

Time-resolved small-angle neutron scattering — •Roland May — Institut Max von Laue - Paul Langevin, BP 156, F-38042 Grenoble Cedex 9, France

Small-angle neutron scattering has a history of about 40 years, but only with the advent of modern fast electronics has it become feasible to penetrate into time regimes that are compatible with reaction rates and process times of biomolecules, polymers and colloids at full detector resolution. Neutron sources cannot compete with the flux or brilliance of X-ray sources. Therefore they are limited as far as the observation of very fast processes is concerned, unless if they can be easily and often repeated, as in cyclic events. Of course, neutrons heave the special advantage of neutron contrast variation, allowing one to highlight parts of a structure, and they do not produce any radiation damage. This contribution will address these technical issues and give a number of examples from the slow kinetics of oil droplet formation to the observation of the photocycle of photo-active yellow protein in the tens of milliseconds range, and also mention how one can reach even shorter times with sophisticated time-of-flight techniques.