Our X-ray Diffraction Equipment

The Experimental Setup

To perform a X-ray diffraction experiment, we need an x-ray source. In most cases a rotating anode generator producing a X-ray beam of a characteristic wavelength is used. Intense, tunable X-ray radiation produced by a Synchrotron provides additional advantages. The primary X-ray beam is monochromated by either crystal monochromators or focusing mirrors. After the beam passes through a helium flushed collimator it passes through the crystal mounted on a pin on a goniometer head. The head is mounted to a goniometer which allows to position the crystal in different orientations in the beam. The diffracted X-rays are recorded using image plates, Multiwire detectors or CCD cameras.

Our Multiwire Detector System Quantum 1 CCD System Quantum 4 CCD System 

Flash cooling protein crystals to cryogenic temperatures (~100 K) offers many advantages, the most significant of which is the elimination of radiation damage. A part of the X-rays passing through the crystal is scattered in different directions into a detector. In our facility we use multiwire detectors and CCD detectors. They all deliver an image of the diffraction spots. A large number of these images recorded from different crystal orientations are processed (scaled and merged) into a final list of indexed reflection intensities.

To learn more about cryo-cooling of crystals click on the picture

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This World Wide Web site conceived and maintained by Bernhard Rupp (br@llnl.gov)
Last revised July 13, 2001 08:49
UCRL-MI-125269