EXPERIENCE WITH MICROCHANNEL AND PIN-POST WATER COOLING OF SILICON MONOCHROMATOR CRYSTALS

Using special channel geometries, the efficiency of water cooling of silicon crystals at room temperature can be improved to the point where it becomes very attractive for use with x-ray monochromators at high-power synchrotron radiation beamlines. Prototype monochromators using two different geometries have been built and tested. The microchannel geometry uses long, parallel channels approximately 50 mu m in width. The pin-post geometry creates a two-dimensional network of submillimeter water passages. Both geometries have excellent thermal performance, though preparing strain-free crystal assemblies containing such small features remains problematic. When perfected, water cooling using microchannel or pin-post geometries should be particularly suited to monochromator crystals used at wiggler beamlines.