Convergent Beam X-ray Diffraction using Polycapillary X-ray Optics. S. M. Owens^*, F. A. Hofmann^*, S. M. Lee^*, C. A. MacDonald^*, D. C. Carter^#, J. R. Ruble^#, R. C. Sisk^Ü, E. H. Snell^Ü, J. B. Ullrich⁺, I. Yu. Ponomarev⁺, and W. M. Gibson^{* *}Center for X-ray Optics, University at Albany, Albany, NY 12222 ^#New Century Pharmaceuticals, Inc., 895 Martin Rd., Huntsville, AL 35824 ^ÜLaboratory for Structural Biology, NASA, MSFC, Huntsville, AL 35812, ⁺X-Ray Optical Systems, Inc., 90 Fuller Rd., Albany, NY 12205

Convergent beams of x-rays, with convergence angles as high as fifteen degrees, have been produced using polycapillary x-ray optics. Focused spot sizes as small as 40 mm have been achieved, with flux densities two orders of magnitude larger than that produced by pinhole collimation. Polycapillary lenses with convergent angles of 2 have transmissions of 10% at 8 keV and provide, additionally, substantial suppression of the high energy Brehmsstrahlung.

Measurements of x-ray diffraction data and crystallographic analysis have been performed for systems ranging from elemental crystals to proteins. The large gains from use of these optics result in a comparable decrease in data collection times due to the increase in direct beam intensity and/or reciprocal space coverage. Data from a lysozyme protein crystal using a slightly convergent beam, taken in 3 minutes per frame with 2 oscillation with a 2.8 kW source, refined to a R_merg factor of 5.7% based on intensities. High quality data was obtained with a 0.035 kW sealed tube source and a 2 convergent lens from a lysozyme crystal in 5 minutes per frame.

Convergent beam x-ray diffraction (CBXD) can be used to gain similar information to convergent beam electron diffraction (CBED) for materials or situations that are incompatible with CBED, such as insulators and in situ analysis. A comparison of CBXD measurements of Si (111) crystals will be made to comparable CBED data.