Jing Chunguang, Liu Wanming, Xiao Liling, Gai Wei, Schoessow P, Wong Thomas
High Energy Physics Division, Argonne National Laboratory, Argonne, Illinois 60439, USA.
Phys Rev E Stat Nonlin Soft Matter Phys. 2003 Jul;68(1 Pt 2):016502. doi: 10.1103/PhysRevE.68.016502. Epub 2003 Jul 21.
By applying different symmetric boundary conditions, we found that the transverse wakefields generated by an electron bunch traveling through a partially loaded rectangular dielectric structure at an off center position can be decomposed into corresponding orthogonal longitudinal section electric (LSE) and longitudinal section magnetic (LSM) modes for guided waves as in the case of longitudinal wakefields treated previously. The wakefields are characterized using the normalized shunt impedance R/Q, a function of the geometry of the accelerating structure, for both LSE and LSM modes. A numerical example is given for an X-band waveguide structure and detailed results are given for the several leading transverse wakefield terms. The analytic results obtained are in agreement with the results from the time domain simulation tool MAFIA.
通过应用不同的对称边界条件，我们发现，电子束在偏离中心位置穿过部分加载的矩形介质结构时所产生的横向尾场，如同之前处理纵向尾场的情况一样，对于导波而言，可以分解为相应的正交纵向截面电（LSE）模和纵向截面磁（LSM）模。对于LSE和LSM模，使用归一化并联阻抗R/Q来表征尾场，R/Q是加速结构几何形状的函数。给出了一个X波段波导结构的数值示例，并给出了几个主要横向尾场项的详细结果。所获得的解析结果与时域模拟工具MAFIA的结果一致。
