用于新型粒子加速器准直安装及动态准直的平滑分析方法研究与验证

Recently, with the development of technology and theory of particle accelerator, modern synchrotron sources represented by free-electron lasers (FELs) and diffraction-limited storage rings and large particle collider will be built in the near future. Comparing with the running accelerators, higher efficiency and accuracy of installation and alignment are required for the new particle accelerators. Measurement and alignment pass through the entire particle accelerator engineering construction processes, working efficiency and accuracy of alignment have a huge influence with the entire engineering construction. It is necessary for all the storage ring magnets to be placed with a high relative accuracy to meet the stringent demands of accelerator physics. We also emphasize the work efficiency and propose many advanced approaches. Experience from other accelerators and synchrotrons all around the world suggests that smoothing analysis is a practical method considering both relative accuracy and work efficiency. Concrete research content including following several aspects: algorithm research of smoothing, coding of smoothing analysis, application method research of smoothing in the dynamic alignment. The research results of smoothing will be independently verified at Hefei light source and Hefei advanced light source engineer construction. The research achievements will provide strong technical support for the Hefei advanced light source and future large accelerators engineer construction.

随着粒子加速器技术的发展，新型粒子加速器工程建设日渐兴起。相较于目前运行的粒子加速器，新型加速器的工程规模更加庞大，对于束流轨道的定位精度及位置稳定性要求也更高。准直测量工作的效率及安装准直精度对整个工程的成功实施有直接影响。根据加速器物理的要求，相对于每个元件的绝对安装精度，相邻元件的相对定位精度更加重要。本课题拟通过平滑分析的方法将磁铁等关键元件的相对位置关系调节到很高的精度，并通过迭代的方法保证整个加速器的高精度相对定位。这一方法还可以用于粒子加速器运行过程中的动态准直，保证整个加速器平稳运行。具体研究内容包括：平滑分析方法的算法研究、平滑分析方法的程序化实现，以及平滑分析方法在动态准直中的应用。本项目拟结合合肥光源的复测数据和合肥先进光源验证装置的工程建设对平滑分析方法进行实际验证并开发一套可初步应用的平滑程序。本项目的研究成果可以为未来大型粒子加速器的工程建设提供有力的技术保障。

近两年来，我国粒子加速器行业迎来重大发展机遇期，包括上海硬X射线自由电子激光、北方光源等项目顺利破土动工。这些新型的粒子加速器工程规模庞大，且对于准直安装精度特别是关键元件相对位置关系的要求非常苛刻。本课题对减小相邻元件间相对偏差值改善粒子加速器束流性能这一问题进行了深入研究。首先，我们研究了包括三次B样条曲线方程、滑动平均算法、Parzen窗函数在内的不同曲线拟合方法的数学模型；然后针对这些不同的轨道平滑算法，基于AT(Accelarator Toolbox)加速器物理模拟计算来验证其工作效率和改善束流物理性能方面的差异，通过模拟验证得知，Parzen窗函数曲线拟合平滑方法相较于其他方案具有调节较少的磁铁能够使光源品质获得更多的改善。我们基于这一算法，使用Javascript编程语言编写了一个可用的束流轨道平滑程序，并基于这一平滑程序对合肥光源的复测数据进行了处理，快速计算出改善合肥光源束流品质所需要调节磁铁的序号和调节量。