In order to improve machine performance, the optics parameters of the storage ring need to be measured accurately. The commonly used accelerator optics parameters, including momentum compaction factor and dispersion function, are key parameters that reflect the state of the machine. It is difficult to measure them with traditional methods during the user operation run. Based on a high-resolution bunch-by-bunch three-dimensional measurement system, a noninvasive measurement of momentum compaction factor and the dispersion function was performed at the Shanghai synchrotron radiation facility (SSRF). The dispersion function can be obtained purely from the direct observation results of the bunch-by bunch 3D position, based on the definition of the dispersion function during normal user operation run without perturbing the beam. The theoretical background and experimental results of the method are discussed in this paper. The measurement results are in good agreement with the design values.

中文翻译：

---

使用逐束 3D 光束位置测量数据对存储环中的光学参数进行无创测量的新方法

为了提高机器性能，需要准确测量存储环的光学参数。常用的加速器光学参数，包括动量压实因子和色散函数，是反映机器状态的关键参数。在用户运行过程中，传统方法很难对其进行测量。基于高分辨率逐束三维测量系统，在上海同步辐射设施（SSRF）进行了动量压缩因子和色散函数的无创测量。色散函数可以纯粹从逐束 3D 位置的直接观察结果中获得，基于正常用户操作运行期间色散函数的定义，而不会扰动光束。本文讨论了该方法的理论背景和实验结果。测量结果与设计值吻合良好。