相对论与加速器工程
Relativity and Accelerator Engineering
摘要：
从几何学的观点来看，根据相对论，空间和时间构成一个具有伪欧几里德结构的四维连续体。这一点最近开始成为加速器物理学中一个实际上很重要的命题。X射线自由电子激光（XFEL）实际上是工程系统中最好的、令人兴奋的例子，加速器技术的改进使开发具有内部精细结构的超相对论宏观物体成为可能，相对论在它们的描述中起着至关重要的作用。在超自由电子激光器中，纳米尺度调制的超相对论电子束团确实具有10 $μ$ m量级的宏观有限尺寸。其内部的集体结构的特征在于波数矢量。在这里，我们将表明，一个四维的几何方法，不寻常的加速器物理，需要解决的问题，涉及从一个超相对论调制的电子束沿曲线轨迹加速辐射的发射。我们将看到，相对论运动学通过调制波数矢量的所谓维格纳旋转以最基本的方式进入XFEL物理学，这与同时性的相对性密切相关。如果不考虑相对论运动学效应，理论和实验之间的定性分歧会很大。在本文中，相对论运动学效应的几个例子，这是重要的，目前和未来的XFEL操作，进行了研究。通过提供实验室帧内的时钟同步过程的细节来应用相对论。这种方法，利用这里，但在文献中不寻常的，是相当“实用”的，应该是可以接受的加速器物理学家。
英文摘要：
From a geometrical viewpoint, according to the theory of relativity, space and time constitute a four-dimensional continuum with pseudo-Euclidean structure. This has recently begun to be a practically important statement in accelerator physics. An X-ray Free Electron Laser (XFEL) is in fact the best, exciting example of an engineering system where improvements in accelerator technology makes it possible to develop ultrarelativistic macroscopic objects with an internal fine structure, and the theory of relativity plays an essential role in their description. An ultrarelativistic electron bunch modulated at nanometer-scale in XFELs has indeed a macroscopic finite-size of order of 10 $μ$m. Its internal, collective structure is characterized in terms of a wave number vector. Here we will show that a four-dimensional geometrical approach, unusual in accelerator physics, is needed to solve problems involving the emission of radiation from an ultrarelativistic modulated electron beam accelerating along a curved trajectory. We will see that relativistic kinematics enters XFEL physics in a most fundamental way through the so-called Wigner rotation of the modulation wave number vector, which is closely associated to the relativity of simultaneity. If not taken into account, relativistic kinematics effects would lead to a strong qualitative disagreement between theory and experiments. In this paper, several examples of relativistic kinematics effects, which are important for current and future XFEL operation, are studied. The theory of relativity is applied by providing details of the clock synchronization procedure within the laboratory frame. This approach, exploited here but unusual in literature, is rather "practical", and should be acceptable to accelerator physicists.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
