功率耦合器是中国散裂中子源(CSNS)漂移管直线段(DTL)的关键部件之一,其耦合系数通常通过调节耦合孔尺寸得到, 为了确保耦合系数达到设计值, 制造了一个冷模进行耦合度的调节。在冷模测量过程中, 发现了仅通过改变耦合孔尺寸耦合系数达不到目标值的问题, 因此提出了一种与测量结果对比有良好仿真精度的新模型用于分析, 并使用该仿真模型分析了PEFP使用的理论及影响耦合度的主要参数。最终耦合度被调节至目标值, 正式件的冷测结果也表明其与仿真结果基本相同。

RF power coupler is one of the key components in China Spallation Neutron Source (CSNS) Drift Tube Linac (DTL), its coupling coefficient is usually obtained by changing the dimensions of coupling hole mechanically. In order to make sure that the coupling coefficient reaches the designed value, a cold model is manufactured for the coupling coefficient adjustments. During the measurement of the cold model, it is found that the coupling coefficient cannot reach the target value by changing the hole diameter only. Therefore, a new simulation model with good accuracy in comparison with measurement results is proposed for analysis, and the theory used in Proton Engineering Frontier Project (PEFP) and the main parameters affecting the coupling coefficient are analyzed accordingly. Finally, the coupling coefficient is adjusted to the target value, and the low power test results of copper model show a good agreement with the simulation results.