漂移管直线加速器加速电场分布及稳定性调谐研究

漂移管直线加速器(DTL)加工和安装的误差会导致腔内加速电场分布偏离设计值。为了补偿该偏差,通常在腔内安装调谐装置。同时,在腔内引入耦合杆周期结构,通过调节耦合杆与漂移管之间的间隙,可提高DTL腔内加速电场的稳定性。本文基于高频谐振腔理论和小球拉线测量技术,搭建了一套高精度电场测量系统。结合仿真模拟和实验,实现了中国散裂中子源(CSNS)DTL的加速电场和稳定性调谐,使得腔内实际加速电场分布与设计值相对偏差小于2%,谐振频率和电场稳定性均达到设计指标。

Design Study on Accelerating Field Distribution and Stability Tuning of Drift Tube Linac

The fabrication and assembly errors of the drift tube linac (DTL)may cause a large discrepancy on the distribution of the accelerating field.The tuner was typically used to compensate the deviation.Meanwhile,a series of post-couplers were introduced to increase the stability of the accelerating field by properly adjusting the gap between post-coupler and drift tube.In this paper,based on RF resonant cavity theory and bead pull technology,a high-precision measurement system was established.Combining the simulation with experiment,the low power resonant frequency tuning of CSNS DTL tank was successfully performed.The relative deviation between real field distribution and design result is less than 2%,and the resonant frequency and stability reach the tuning objective.