四路激光在合肥先进光源预准直及其布局优化  

Layout Optimization of Four-Channel Laser Pre-Alignment System for Hefei Advanced Light Facility

作　　者：丁婷 王巍[1] 李笑 徐蒋林 张思成 程竹兵 吴恩辰 张秋雨 何晓业[1] Ding Ting;Wang Wei;Li Xiao;Xu Jianglin;Zhang Sicheng;Cheng Zhubing;Wu Enchen;Zhang Qiuyu;He Xiaoye(National Synchrotron Radiation Laboratory,University of Science and Technology of China,Hefei 230029,Anhui,China)

机构地区：[1]中国科学技术大学国家同步辐射实验室,安徽合肥230029

出　　处：《中国激光》2024年第14期153-161,共9页Chinese Journal of Lasers

摘　　要：为提高磁铁单元预准直精度和工作效率,基于合肥先进光源设计了一套四路激光系统进行磁铁预准直。由于在实际布设四路激光系统时难以满足设计的角度和距离要求,针对影响四路激光布局精度的因素,着重分析了角度和距离对布局精度的影响规律,采用拟合误差指标和USMN (Unified spatial metrology network)权重分配优化平差方法进行四路激光系统的布局优化。通过优化USMN功能参数降低角度权重来提高磁铁单元预准直精度和工作效率;在定量分析粒子束的位置时,相比于其他指标,拟合误差比PDOP (Position dilution of precision)更能反映横向精度的变化,在粒子加速器准直测量领域更具优势。根据布局优化结果分析,直角正三棱锥为最佳布局,该布局的磁铁单元横向精度为7.5μm,满足合肥先进光源对磁铁单元预准直精度为10μm的要求。布局的角度会影响误差分布,且不同方向上的距离对精度的敏感程度有差异。所提设计对于四路激光系统实际布设具有一定的指导意义。Objective The Hefei Advanced Light Facility(HALF) is an international, advanced, fourth-generation synchrotron radiation light source in the low-energy region with world-leading design specifications for emissivity and brightness. However, challenges arise in the construction and operation of the HALF, one of which is the method to efficiently perform highly accurate pre-alignments. To improve the magnet pre-alignment accuracy and work efficiency, members at the HALF design a four-channel laser system for prealignment. Owing to space limitations, the actual four-channel laser system cannot fulfill the theoretical angle and distance requirements. Hence, the best layout for a four-channel laser system must be determined and the effects of angle and distance on the layout accuracy must be analyzed to improve the measurement performance of the four-channel laser system. Additionally, a simple and rapid adjustment method and an evaluation indicator suitable for accelerator alignment measurements are used to improve the efficiency of the four-channel laser system.Methods Fitting-error indicators and the unified spatial metrology network(USMN) weight-allocation-optimization adjustment method were used to optimize the layout of the four-channel laser system. The USMN weight-allocation-optimization adjustment dynamically adjusted the divergence-angle parameters to determine the most suitable parameter combination, reduce the angle weight, and improve the measurement accuracy. Meanwhile, the fitting-error evaluation was based on magnet points. The measured and theoretical values were used to perform a fitting conversion to obtain the fitting errors. We strictly derived the relationship between the fitting error and four-channel laser layout error and confirmed that the fitting error can be used as an indicator to evaluate the accuracy of the four-channel laser layout. The effects of angle and distance on the layout accuracy were analyzed to improve the measurement performance of the four-channel laser system.Results and Di

关 键 词：合肥先进光源 四路激光 空间联合精密控制网 拟合误差 布局 

分 类 号：P258[天文地球—测绘科学与技术]