SSRL, Bldg. 137, Rm. 322
Martin Fuchs, MX Group, Swiss Light Source; Paul Scherrer Institute (Villigen, Switzerland)
A new unified diffractometer – the D3 – has been developed for the three MX beamlines. The first of the instruments is in general user operation at beamline X10SA since April 2012.
The varied demands from both challenging academic research projects as well as high throughput industrial applications on today’s macromolecular crystallography beamlines drive developments to both endstations and beamline optics. Recent instrumentation upgrades to the macromolecular crystallography (MX) beamlines of the Swiss Light Source therefore aimed to enhance both their performance as well as their reliability.
Building upon and critically extending the developments realized for the high-resolution endstations of the two undulator beamlines X06SA and X10SA, as well as the super-bend dipole beamline X06DA, the new diffractometer was designed to the following core design goals:
Redesign of the goniometer to a sub-micrometer peak-to-peak sphere of confusion for the horizontal single axis, for crystal sizes down to 5 microns. In addition it can accommodate the new multi-axis goniometer PRIGo (Parallel Robotics Inspired Goniometer).
On-axis micro-spectrophotometer MS3 for microscopic sample imaging with one micron image resolution. The multi-mode optical spectroscopy module is always online and supports in-situ UV/Vis absorption, fluorescence and Raman spectroscopy. It is complemented by a complete off-line facility, the SLS SpectroLab, adjacent to the beamline.
Further features are a rapid-change beam-shaping element system, a mineral cast support construction, the support for in-situ crystallization plate screening, close containment of the cryo-stream, and a minimum achievable detector distance of 120 mm for the Pilatus 6M detector.
Concurrent to the upgrade of the experimental endstation, the double-crystal monochromators (DCM) of the two undulator beamlines are being upgraded, with the aim to significantly speed up energy changes and reduce thermal drifts. By exchanging the motors of the Bragg angle axes for nanometer-resolution linear motors, the time for an energy sweep over the complete range from 6 to 20 keV was reduced to below 45s.
