9-cell超导腔快速预调谐方法研究

对频率和场平坦度的预调谐是9-cell超导腔耗时最多的后处理工序之一，很快将成为国内相关大科学工程9-cell腔批量生产的瓶颈。首先介绍了9-cell超导腔两种常用的预调谐方法，即DESY方法和Cornell方法的原理，建模分析和比较了两种方法的计算精度和误差来源，给出Cornell方法调谐量计算的修正。然后结合9-cell超导腔预调谐实验研究，给出了快速预调谐方法:DESY的重建算法在低场平时精度较高且收敛迅速，可作为粗调；Cornell微扰算法在高场平时精度较高且测量迅速，可作为微调。结合两种调谐方式，将预调谐分为粗调和微调两步，可有效提升9-cell超导腔预调谐的速度。

Research on fast pre-tuning method of 9-cell superconducting cavities

The pre-tuning of frequency and field flatness is one of the most time-consuming post-processing procedures for 9-cell superconducting cavities, and will soon become the bottleneck of mass production of 9-cell cavities in domestic related major scientific projects. In this paper we firstly introduce two commonly used pre-tuning methods for 9-cell superconducting cavities, namely DESY method and Cornell method. Then we analyze and compare their calculation accuracy and error sources by modeling, and make a correction on the Cornell method’s tuning amount calculation. Verifing the pre-tuning of several cavities by the experimental research, we give a fast pre-tuning method in which DESY reconstruction algorithm is used for coarse-tuning as it has high precision and rapid tuning speed in low field flatness and Cornell perturbation algorithm is used for fine-tuning as it has high precision in high field flatness with faster measurement. Combining these two tuning algorithms, the pre-tuning is divided into two steps: coarse tuning and fine tuning, which can effectively improve the pre-tuning speed of the 9-cell superconducting cavity.