ASYMMETRIC FRAUNHOFER-DIFFRACTION FROM ROLLER-BLADE SLITS

X-ray diffraction experiments under coherent conditions have been made possible by the development of new sources of synchrotron radiation, but make tough demands on the experimental apparatus. Here we describe the design and initial testing of a precision aperture that uses poli shed molybdenum rods as the slit blades. The device has an inherent as ymmetry which is accurately accounted for by a simple modification to the Fraunhofer diffraction function.