JACoW is a publisher in Geneva, Switzerland that publishes the proceedings of accelerator conferences held around the world by an international collaboration of editors.
TY - CONF AU - Chen, J. AU - Du, X.W. AU - Lin, M.H. AU - Wang, Q.P. AU - Wang, Z. ED - Schaa, Volker R.W. ED - Bian, Lin ED - Chen, Zhichu ED - Dong, Yuhui ED - He, Ping TI - Optimizing Indirect Cooling of a High Accuracy Surface Plane Mirror in Plane-Grating Monochromator J2 - Proc. of MEDSI2023, Beijing, China, 06-10 November 2023 CY - Beijing, China T2 - International Conference on Mechanical Engineering Design of Synchrotron Radiation Equipment and Instrumentation T3 - 12 LA - english AB - For the cooling of the plane mirror in VIA-PGMs (var-iable-included-angle plane-grating monochromators), the top-side indirect cooling based on water is preferred for its advantages, such as cheaper, easier to use, smart notches, etc, when compared to the internal cooling. But it also arises challenges to control the RMS residual slope error of the mirror, whose requirement is less than 100 nano-radian. This requirement is even hard to fulfill, when combined with 1) the asymmetry thermal defor-mation on the meridian of the footprint area during the energy scanning, 2) the high heat load deduced by the synchrotron light and 3) the no obvious effects of the classical optimizations, such as increasing footprint size, cooling efficiency or adding smart notches. An effective way was found after numerous attempts, which is to make the footprint area far from the mirror¿s edge to reduce the asymmetry of the thermal deformation except for leading to a longer mirror. This paper will illustrate how the asymmetry affects the mirror¿s residual slope error and then, focus on the relationship among the asymmetry of cooling and the distance to provide a ref-erence for optical cooling. PB - JACoW Publishing CP - Geneva, Switzerland SP - 280 EP - 282 KW - synchrotron KW - optics KW - SRF KW - brightness KW - ECR DA - 2024/07 PY - 2024 SN - 2673-5520 SN - 978-3-95450-250-9 DO - doi:10.18429/JACoW-MEDSI2023-THPPP007 UR - https://jacow.org/medsi2023/papers/thppp007.pdf ER -