Biological Small Angle X-ray
Scattering/Diffraction
Bridging atomic-resolution structures to molecular/subcellular structures
SSRL Beam Line 4-2 is dedicated to biological small angle x-ray scattering and diffraction studies, and is a part of the structural molecular biology (SMB) user facilities, supported by the National Institutes of Health, the National Center for Research Resources and by the Department of Energy, Office of Biological and Environmental Research. This experimental station, operational for over two decades, received extensive upgrades of beam line optics and in-hutch instrumentation in 2008, and takes full advantage of SPEAR3, a third generation storage ring operational since 2004. The instrument features state-of-the-art experimental facilities for solution scattering, lipid membrane diffraction, fiber diffraction and single crystal diffraction at moderately high to very small scattering angles in the characteristic lengths of the order of microns to a few Ångstroms. These techniques allow structural studies of biological macromolecules and assemblies in physiological or near physiological conditions, complementing high resolution structural techniques which require experimental conditions that are not necessarily physiological. In addition to providing user- friendly experimental facilities for equilibrium studies, BL4-2 maintains premier experimental facilities for time-resolved studies in the millisecond time scale and above.
After the extensive upgrades of beam line optics and in-hutch instrumentation in 2008, the new BL4-2 station has:
- Higher beam flux level by a factor of 5 at 100mA (20 pole 2.0T wiggler)
- Improved beam focus quality (new water cooled mirror)
- Extended energy range: 6-14keV (Si(111) + multilayers)
- New detectors for equilibrium and time-resolved studies
- Automated distance change, covering 2-2000 Å characteristic lengths
- Upgraded Blu-ICE for experimental control
- Specialized sample handling devices for equilibrium, high-throughput and time-resolved studies
|
