A VACUUM CHAMBER FOR LOW-BACKGROUND DIFFRACTION EXPERIMENTS

We developed a small vacuum chamber for very low background single cry stal diffraction experiments. The chamber has been designed for a larg e Eulerian cradle. The phi and chi rotations are not limited by the ch amber, while the omega rotation is limited to a cone of 20 degrees ope ning angle. A crucial part of the design is the position of the beam s top inside the vacuum, eliminating any scattering at the exit windows. The chamber effectively eliminates any air scattering of the primary beam, creating a very low background for single crystal diffraction ex periments.