CHESS X-ray measurements 11/2007

In November, 2007 we had a second week of beam time at CHESS in Cornell University. Participating in this run were CHESS staff scientist Ken Finkelstein, and GlueX collaborators Richard Jones, Franz Klein, and Guangliang Yang. Ken had mounted a new pair of silicon crystals in the primary monochromator box. These crystals were only a couple mm thick, and about 10cm x 10cm in size. Each bounce gave an expansion factor close to 4, with a combined b in the range 16-18. This expanded the beam vertically to about 1.5 cm. The monochromator design is described here. It is dispersion-matched to the diamond 220 reflection. We measured rocking curves for several good diamond crystals (100 microns thick) during this run and demonstrated rocking curve resolution better than 10 μr RMS.