Energy spectra from electromagnetic fields generated by ultra-relativistic charged bunches in a perfectly conducting cylindrical beam pipe
Energy spectra from electromagnetic fields generated by ultra-relativistic charged bunches in a perfectly conducting cylindrical beam pipe
复制标题
完美导电圆柱形束管中超相对论带电束团产生的电磁场的能谱
DOI：
10.1088/1751-8113/43/2/025402
复制
发表时间：
2010
期刊：
影响因子：
--
通讯作者：
Hale A
中科院分区：
文献类型：
--
作者：
Hale A
讨论了满足完全导电边界条件的圆截面直束管段内的电磁场谱与各种源模型的关系。其中包括沿管道轴线匀速运动的带电束，由此导出了束管内麦克斯韦方程组初边值问题的精确解。在超相对论性极限下，所有场的纵向分量都趋于零，横向场的频谱含量和穿过束管任意截面的平均总电磁能量与超相对论性源的某些性质直接相关。结果表明，轴对称超相对论束的干涉效应类似于循环机器中相干同步辐射产生的干涉效应，尽管在这个极限内源没有加速。结果提供了场的解析描述，显示了增强的光谱行为如何取决于源的几何形状，它在束管中的位置以及源结构随机分布的细节。结果说明了与轴上超相对论束的运动有关的不同情况。将包含相同带电超相对论脉冲的源的场能谱（每个脉冲的纵向高斯分布按紧致支持下的均匀概率分布）与在紧致支持下的区域（模拟微束）中包含2n+ 1个峰分布的带电束产生的场能谱进行比较。这些结果对于利用相关电磁能谱的观测来确定束流管直段中具有微观结构的短相对论性电子束的纵向电荷分布特性具有重要意义。
The spectrum of electromagnetic fields satisfying perfectly conducting boundary conditions in a segment of a straight beam pipe with a circular cross-section is discussed as a function of various source models. These include charged bunches that move along the axis of the pipe with constant speed for which an exact solution to the initial-boundary value problem for Maxwell's equations in the beam pipe is derived. In the ultra-relativistic limit all longitudinal components of the fields tend to zero and the spectral content of the transverse fields and average total electromagnetic energy crossing any section of the beam pipe are directly related to certain properties of the ultra-relativistic source. It is shown that for axially symmetric ultra-relativistic bunches interference effects occur analogous to those that occur due to coherent synchrotron radiation in cyclic machines despite the fact that in this limit the source is not accelerating. The results offer an analytic description of the fields showing how enhanced spectral behaviour depends on the geometry of the source, its location in the beam pipe and the details of the stochastic distribution of the source structure. The results are illustrated for different situations associated with the motion of on-axis ultra-relativistic bunches. The field energy spectra associated with a source containing identically charged ultra-relativistic pulses, each with individual longitudinal Gaussian profiles distributed according to a uniform probability distribution with compact support, is compared with that generated by charged bunches containing a distribution with 2n+ 1 peaks in a region with compact support (modelling micro-bunches). These results are of relevance for the experimental determination of properties of the longitudinal charge distribution of short relativistic electron bunches with micro-structure in straight segments of a beam pipe, from observation of the associated electromagnetic energy spectra.
影响因子：
0.7
作者：
R. Tucker
通讯作者：
R. Tucker
影响因子：
1.3
作者：
Goto S
通讯作者：
Goto S
束管中带电相对论源动态增强电磁场的各个方面
DOI：
--
发表时间：
2009
期刊：
影响因子：
--
作者：
A. Hale
通讯作者：
A. Hale