Hermes Group
Instrumentation for structural research at EMBL Hamburg
The multilayer monochromator in its vacuum vessel during installation at beamline BW7A. From right to left (beam direction) first and second multilayer located on their respective positioning devices and the slit system with integrated intensity monitor are shown.
Previous and current research
Research carried out at the Hamburg outstation since 1974 has covered a broad spectrum of X-ray methods used for structural investigations in biology. Small angle solution scattering (SAXS) allows the study of biologicalmacromolecules and their complexes in their native environment, while the complete 3D picture can be obtained by protein X-ray crystallography (PX), amethod which has become the dominant structural research tool in molecular biology not only at synchrotron radiation sources.
Each of the above-mentionedmethods has specific instrumentation needs, and our group designs, constructs and builds the appropriate equipment. Our activities include mechanical engineering, vacuum technology, X-ray optics, data acquisition and control electronics. During 2007 a Multilayer Monochromator (ML) system was designed, built, installed and commissioned on wiggler beamline BW7A which can be used alternatively to the standard optical set-up of this branch of the BW7 wiggler comprising a focussing Si(111) double crystal monochromator (DCM) for MAD data collection on protein crystals. The ML mode of operation was used very successfully in 2008 for PX experiments. This wasmainly due to the considerable gain in intensity, allowing very rapid data collection and hence collecting data froma large number of crystals per shift. In these measurements the newly developed beamline control system which is based on economic industrial electronics and improved software proved to be reliable and user-friendly. In preparation and as test cases for the new beamlines on the worldwide unique radiation source PETRA III, we are in the process of optimising the end-stations of the ‘old’ beamlines at the storage ring.We plan to install for example improved rotation axes, centring devices and automatic sample changers to obtain results which will give us confidence for future applications at PETRA.
Future projects and goals
We will continue to improve the spectral quality of our existing beamlines, while at the same time we plan to make our lines more user-friendly. This also means that we will continue to increase the level of automation of our experimental stations, which is a necessary condition to performhigh-throughput data collection.
EMBL is building and will operate three beamlines on PETRA III. In this context, major challenges and opportunities in the field of beamline instrumentation, sample handling, control electronics and software will have to be mastered (see the Fiedler group, page 99).
The opening of the European X-Ray Laser (XFEL) in Hamburg is scheduled for 2014, offering unprecedented research opportunities. To design experiments which will exploit the potential of this unique facility requires a large number of problems in various areas to be addressed and solved.
Our goal is to create optimal conditions for state-of-the-art experiments in structural biology at amodern synchrotron radiation source.