Research and optimization of flow-induced vibrations in a water-cooled monochromator

To enhance the stability of the water-cooled double-crystal monochromator used at the BL17B beamline of the Shanghai Synchrotron Radiation Facility (SSRF), a study was conducted to optimize its cooling system's flow-induced vibration. Through simulation and experimental verification, the researchers analyzed the vibration mechanism and implemented improvement measures. The results indicate that the elastic bellows greatly amplify flow-induced vibration, transmitting it to the first-crystal. By positioning the bellows closer to the crystal, the relative pitch angular vibration of the double-crystal was reduced by 17.5%, and the roll angular vibration decreased by 6.1%. Furthermore, changing the flow rate from 3 to 2.4 l/min further diminished the relative pitch angular vibration by 6.0% and the roll angular vibration by 7.9%. By effectively reducing flow-induced vibration in the water-cooled double-crystal monochromator, equipment stability is enhanced, and the relative angular vibration of the double-crystal has been reduced. This research provides a valuable method and approach for optimizing the stability of the monochromator and related equipment.