【摘要】 同步工作点的精确测量对于束流纵向动力学研究和束流稳定性提高都有着非常重要的意义。上海同步辐射光源搭建了一套逐束团三维位置诊断系统,可用于实时监测同步工作点。对比传统测量方法,该方法主要关注的是注入瞬态过程,不需要对高频腔压进行调制,在正常供光模式下即可实现同步工作点的高精度测量,不会干扰用户实验;重点观测补注电荷的纵向相位振荡,根据数学模型拟合出多个纵向参数,包括同步工作点。测量结果表明:上海光源同步工作点为0.007 3,拟合精度为95%;通过公式计算得到的储存环动量紧缩因子为4×10-4。更多还原

【Abstract】 [Background]The precise measurement of the synchrotron tune is of great significance for the study of beam longitudinal dynamics and the improvement of beam stability. In 2020, a bunch-by-bunch 3 D position diagnosis system to measure the transverse position and longitudinal phase was built at Shanghai Synchrotron Radiation Facility(SSRF), it can also be used to monitor synchrotron tunes in real time. Compared with the traditional measurement method, the advantage of this method is that it does not need to modulate the RF cavity pressure. [Purpose]This study aims to achieve high-precision measurement of synchrotron tune in the normal operating mode without disturbing the user’s experiments. [Methods]The phase oscillation of the refilled charge during the injection transient was extracted to effectively remove the interference of the RF system and the crosstalk between bunches. Correlation coefficient was used to obtain the bunch phase refilled with charge. Then, multiple longitudinal parameters, including the synchrotron tune, were fitted by mathematical model. [Results]The measurement results show that the synchrotron tune of SSRF is 0.007 3, and the fitting accuracy is 95%. The momentum compaction factor of storage ring directly calculated by the formula is 4×10-4. [Conclusions]The bunchby-bunch 3 D position diagnosis system and refilled charge extraction algorithm provide a favorable tool for realizing high-precision measurement of synchrotron tune.更多还原