Micro-focus Macromolecular Crystallography

Beam line 12-2 is a PRT station, realized through third party funding from the Gordon and Betty Moore Foundation via the California Institute of Technology and available to general users 70%; it is a 134-pole, 1.0-Tesla in-vacuum undulator beam line with fully adjustable focus from 100 to 15 microns. smaller beams can be achieved by the use of microcollimators. It is optimized for microdiffraction, monochromatic, high-throughput and high-resolution macromolecular crystallography. It is SAD and MAD capable and can be run in a full remote access mode.

Beam line 12-1 employs a 154-pole, 1-Tesla in-vacuum undulator, a flat side-deflecting Rh-coated Si mirror, and a liquid nitrogen-cooled double-crystal Si(111) monochromator with a 0.01% energy bandpass. The beamline is also fitted with a multilayer with a ~1% energy bandpass that boosts the x-ray flux by a factor by about two orders of magnitude.. Kirkpatrick-Baez (KB) optical mirrors are used for 18:1 horizontal and 12:1 vertical beam focusing. The vertical mirror polish is ~100 nrad RMS and a vertical beam focus of ~5 µm FWHM.