衍射极限储存环物理设计研究进展

总结了国内外在衍射极限储存环（DLSR）物理设计方面的研究进展。为了在合理的周长范围内实现超低束流发射度，DLSR线性束流光学设计普遍采用紧凑型多二极铁消色散结构。在非线性动力学优化中，通常采用相移控制技术、解析和数值优化技术减小由色品六极铁导致的强非线性效应。DLSR束流接受度较小，主要考虑脉冲多极铁偏轴注入和快速冲击磁铁在轴注入两种注入方案。束流集体效应（尤其是束流内部散射和托歇克散射效应）随发射度降低而增强，需要采用束长拉伸、横向反馈等方法提高DLSR中束流的稳定性。

Advances in physical design of diffraction-limited storage ring

A new generation of ring-based light source, called diffraction-limited storage ring (DLSR), has attracted increasing attention from accelerator scientists worldwide. This article introduces the progress in the physical design and optimization of DLSR at home and abroad in the past few years. In the linear optics design multi-bend achromats with compact layout are usually adopted, so as to achieve ultralow emittance within a reasonable circumference. In the nonlinear optimization, phase manipulation technique, theoretical and numerical optimization methods are usually used to minimize the strong nonlinearities caused by the chromatic sextupoles. Associated with the small acceptance of a DLSR, off-axis injection with pulsed multipoles and on-axis injection with fast kickers are considered. Collective effects, especially the intrabeam scattering and the Touschek effects, become significant as emittance decreases, requiring methods of bunch lengthening and transverse feedback to ensure the stability of the particle motion.