Eppley Institute for Cancer Research

University of Nebraska Medical Center

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Experimental Setup

Ripple works with a dual detector layout.  The setup for an experiment that Ripple will help collect is detailed below:

Ripple uses works with two detectors.  The first is a normal large field of view protein crystallography detector like an ADSC Quantum IV or similar.  The second is a topography detector.  Typically this detector will have a small field of view but an extremely high spatial resolution (<10um).  Experimentally the large detector and conventional software is used to index the crystal and locate reflections for topography.  The normal detector is removed and the topography detector is positioned at the locations of selected reflections.

The X-Ray beam must have some specific conditions.  First it must be parallel.  Second it must be monochromatic.  Third it should be very intense.  These conditions are necessary to minimize the beam effects that will be measured at the detector from the mosaicity effects we are actually trying to measure.  The more intense the beam the quicker frames can be collected and the less likely a beam dump will occur during the experiment.  Currently, these conditions can only be obtained at a synchrotron source where the beam line is operating in unfocused mode.

Mechanically the goniometer should be capable of very small accurate movements in phi.  Depending on the available equipment the limiting factor for the phi slice will probably be due to how accurate the mechanics of the goniometer are.  It may be necessary to have the equipment modified to use phi steps on the order of 0.001 degrees.

Currently, Ripple only supports the EDC-2000S, ADSC (All detectors) and the MarCCD formats for displaying images.

For collecting images Ripple only supports the EDC-2000S.

For positioning of the Detector Ripple only supports the Velmex BiSlide positioner.

All of the topography images should to be collected with the same detector settings.