Alignment system for crossed parabolic x-ray mirrors

We describe the implementation of a crossed graded parabolic x-ray mirror s ystem that is suitable for incorporation into both conventional and high re solution x-ray diffraction systems. A novel optical alignment system has be en devised that permits independent adjustment of the positions and the ang ular settings of the mirrors. This alignment system is simple and inexpensi ve to construct, yet is mechanically stable and easy to use. The crossed mi rror system has been successfully introduced into both protein crystallogra phy and high resolution x-ray diffraction systems. (C) 2000 American Instit ute of Physics. [S0034-6748(00)04106-X].