A directly water-cooled silicon crystal for high power insertion devices

Directly water-cooled silicon crystals with various types of water channels and cooling fins were fabricated and tested at the 27-pole wiggler beamline BL13 of the Photon Factory. Double-crystal rocking curves for a Si(111) reflection indicated that the performance of a grooved silicon crystal in cooling efficiency is significantly improved by replacing conventional semicircular water channels and cooling fins with flat ones with optimum dimensions. For this design, the width of a Si(111) rocking curve was independent of a wiggler power within 2/3 of the full power. In this power range, a highly stable monochromatized beam with an energy resolution required in x-ray absorption near-edge structure experiments (ΔE/E∼2x10-4) was obtained. copyright 1995 American Institute of Physics