Instrumentation for structural research
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.
Activities in the Hermes team include designing and constructing equipment for mechanical engineering, vacuum technology, X-ray optics, data acquisition and control electronics.
Previous and current research
Small angle solution scattering (SAXS) allows the study of biological macromolecules and their complexes in their native environment, while the complete, detailed 3D picture can be obtained by protein X-ray crystallography (PX), which has become the dominant structural research tool in molecular biology. Each of these methods have specific instrumentation needs, and our group designs, constructs and builds the appropriate equipment.
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 focusing 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.
As the intensity levels available in ML mode are identical to the values expected at PETRA III (although the beam is far less focused and monochromatic) this beamline has, for over a year, been operating as a test station for equipment to be potentially used at the new EMBL beamlines at PETRA III. These tests are providing extremely useful information on layout and design parameters of instruments built in-house, as well as in assessing the usefulness of commercial components. The newly developed beamline control system, based on economic industrial electronics and improved software, has proven both reliable and user-friendly.
We are continuously optimising the end-stations of the ‘old’ beamlines at the DORIS storage ring through the continual development of our automatic sample changer for protein crystals. is is the prototype of instruments foreseen to be installed at the PETRA III PX beamlines.
Future projects and goals
We will continue to improve the spectral quality of our existing beamlines, while at the same time we aim 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 perform high-throughput data collection.
EMBL is building and will operate three beamlines on PETRA III. Major components are currently being installed and will undergo extensive testing before being commissioned. In this context, very close collaboration between instrumentation and scientific groups will be required, to both rise to challenges and create opportunities in the fields of beamline instrumentation, sample handling, control electronics and software (see Fiedler team). The opening of the European X-Ray Laser (XFEL) in Hamburg is scheduled for 2014, offering unprecedented research opportunities. Designing experiments that can exploit the potential of this unique facility requires us to overcome a large number of problems in various areas and at the same time presents great potential for signi cant advancements in structural research.
Our ultimate goal is to create optimal conditions for state-of-the-art experiments in structural biology at a modern synchrotron radiation source.