W0082

New X-ray Optics for Protein Crystallography. Boris Verman, Licai Jiang, Yuriy Platonov, Doug Wilcox, Jim Rodrigues, Nick Grupido, Osmic, Inc., 1900 Taylor Rd., Auburn Hills, MI 48326, Cheng Yang, Adam Courville, Angela Criswell, Kris Tesh, Joseph D. Ferrara, MSC, 9009 New Trails Dr., The Woodlands, Texas USA 77381.

Systems based on rotating anode X-ray generators coupled to a focusing multilayer optic (two focusing planes) are currently the most common laboratory sources for protein crystallography. Recently developed high-brilliance rotating anode generators have improved system performance over conventional X-ray generators. Our presentation considers the optimal combination of the source and optic for these new generation sources.

Ray tracing simulations were used for predicting and analyzing system performance. Since there is no firm criterion for system optimization, the trade-off between system flux and resolution was considered as a variable for the overall system quality description. As a result of the optimization study, a new optic was designed to enhance system performance. The new optic was first tested to prove that the predicted and measured X-ray beam parameters are in agreement. The measured flux and beam cross sections at both sides from the optic focal plane was found to be in satisfactory agreement with the results of simulation and proved the enhanced beam performances as compared with standard optics. Finally, data collections were performed on the standard and new systems using several different protein crystals. Comparisons of the resultant data sets will be presented.