发表机构
Fermi National Accelerator Laboratory（费米国家加速器实验室）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文介绍为费米实验室Linac2调试开发的自动化ORM测量与四极磁铁对中工具，通过低振幅多频率激励和DFT分析实现，并在400 MeV直线加速器上测试验证。
AI 中文摘要
为准备费米实验室Linac2（原称PIP-II直线加速器）的调试，我们正在开发高层应用，用于自动化轨道响应矩阵（ORM）测量和基于束流的四极磁铁磁中心定位。这两种程序均设计为在低振幅模式下运行，与常规运行兼容。ORM的测量方法是同时以低振幅激励多个偶极校正器，每个校正器使用不同的频率，并对记录的BPM信号应用离散傅里叶变换，以提取每个元件的传递函数并量化噪声。测量得到的ORM的一个应用是预测形成局部轨道扰动（凸轨）的校正器系数。为了在四极磁铁中使轨道对中，在其周围产生这样的凸轨，振荡四极磁铁电流，并记录和分析下游BPM的响应。在四极磁铁内的多个束流位置（每个位置由凸轨设定）重复此过程，BPM信号对束流位置的依赖关系提供了关于四极磁铁中心的信息。这些应用正在费米实验室400 MeV直线加速器的常规生产运行期间进行测试，所获得的经验反馈到其改进中。
英文摘要
In preparation for the commissioning of Linac2 (formerly referred to as the {PIP-II} linac) at Fermilab, we are developing high-level applications that automate Orbit Response Matrix (ORM) measurement and beam-based localization of quadrupole magnetic centers. Both procedures are designed to run in a low-amplitude mode compatible with otherwise regular operation. The ORM is measured by exciting multiple dipole correctors simultaneously at low amplitude, each at a distinct frequency, and applying a Discrete Fourier Transform to the recorded BPM signals to extract per-element transfer function with quantified noise. One application of the measured ORM is to predict the corrector coefficients that form local orbit perturbations (bumps). To center the trajectory in a quadrupole, such a bump is created around it, the quadrupole current is oscillated, and the responses of the downstream BPMs are recorded and analyzed. Repeating this at several beam positions inside the quadrupole -- each set by the bump -- the dependence of the BPM signal on beam position provides information about the quadrupole center. The applications are being tested at the Fermilab 400\,MeV Linac during regular production runs, and the lessons learned are fed back into their improvement.
