衍射极限的电子储存环物理设计及组合功能磁铁设计研究

项目名称： 衍射极限的电子储存环物理设计及组合功能磁铁设计研究

项目编号： No.10875127

项目类型： 面上项目

立项/批准年度： 2009

项目学科： 轻工业、手工业

项目作者： 李为民

作者单位： 中国科学技术大学

项目金额： 39万元

中文摘要： 储存环光源具有高稳定性、高效率的独特优势，成为光子科学发展的强劲推动力。随着束流发射度降低，动力学孔径问题成为限制光源表现的主要瓶颈。在第三代同步辐射光源发展历程中，发展了各种基于非线性指示量的动力学孔径和动量孔径优化方法，随着衍射限电子储存环的提出，非线性效应更严重，发展更高效的非线性优化工具，对于研究衍射限储存环的可行性与提高性价比是必要的。近年了计算机科学与技术的发展，为各个学科的研究提供了新的方法与更强大的计算能力。项目研究中，首先提出了以量化的动力学孔径代替传统的非线性指示量作为主要优化目标，以静态非线性参数为辅助优化目标，更有效地判断设计参数的物理性能优劣；然后，发展了基于人工智能算法的参数优化方法，人工智能算法的强大的全局寻优能力确保能够寻找到最理想的设计参数；程序并行化后，现代计算机群的强大计算能力令储存环lattice设计更容易进行。基于上述理论发展的程序应用于合肥先进光源储存环和合肥光源储存环的物理参数设计研究，计算结果显示了新方法寻找最优化设计参数的强大能力，为未来多目标的集成参数优化奠定了基础。

中文关键词： 衍射限储存环；终极储存环；动力学孔径；人工智能算法；并行计算

英文摘要： Ring-based light sources, which are more efficient and stable compared to other synchrotron radiation light source schemes, have became main promotion and supports to photon science and technology. With decreasing beam emittance, dynamic aperture issues are getting more severe and become bottleneck effects for light source performance. In the history of third generation electron storage ring, various optimization methods based on traditional indicators of nonlinear effects were developed to enlarge dynamic aperture and momentum aperture. Raising the concepts of diffraction-limited storage ring or ultimate storage ring, new nonlinear optimization methods and tools are urgent for fearful nonlinear effects in the feasibility study. Fortunately, fast developments of computer science and technology have brought new opportunities to many research areas, including accelerator physics.In this item, quantitative criteria were proposed to judge the quality of dynamic aperture of storage ring firstly, and traditional static nonlinear parameters were selected as auxilliary optimization goals. Then, optimization methods based on artificial intelligence algorithm, which have more powerful global-searching ability compared with traditional mathematical methods, were developed to find the compromise solutuons between beam emittance and dynamic aperture. Considering amazing enhancement of computer cluster, codes were parallelized and the efficiency was improved with several hours searching time. To illustrate the capability of new developed tools, upgraded Hefei Light Source storage ring and proposed Hefei Advanced Light Source storage ring were used as examples. For former case, solutions of global minimum emittance magnet lattice were found, and for latter case, solutions of magnet lattice with acceptable dynamic aperture and minimum beam emittance were obtained. The preliminary results showed the effectiveness of new developed codes, which would become the basis of multi-objective and integrated overall optimization of ultimate storage ring.

英文关键词： Diffraction-limited storage ring; Ultimate storage ring; Dynamic aperture; Artificial intelligence; Parallel computing