ALSNews is a biweekly electronic newsletter to keep users and other interested parties informed about developments at the Advanced Light Source, a national user facility located at Lawrence Berkeley National Laboratory, University of California. We welcome suggestions for topics and content.
Previous Issues are available.
The coherent light provided by lasers revolutionized experimental science in many ways. To study thermally driven fluctuations inside molecules, a group of scientists at the ALS has applied coherent soft x rays from Beamline 7.0.1 to dynamic scattering experiments on liquid-crystal films. At the molecular scale, a longer wavelength is not detrimental to resolution. The goal is to develop this technique so that it can be used to probe fluctuations during phase transitions and to study the internal motions of biological molecules that are thought to be crucial to chemical reaction rates, catalysis, and biological function. When photons are reflected from this fluctuating system, the intensity of the reflected beam will fluctuate because of the thermally driven motions within the sample.