Modern electron linear accelerators are often designed to produce smooth bunch distributions characterized by their macroscopic ensemble-average moments. However, an increasing number of accelerator applications call for finer control over the beam distribution, such as by requiring specific shapes for its projection along one coordinate. Ultimately, the control of the beam distribution at the single-particle level could enable new opportunities in accelerator science. This review discusses the recent progress toward controlling electron beam distributions on the “mesoscopic” scale with an emphasis on shaping the beam or introducing complex correlations required for some applications. This review emphasizes experimental and theoretical developments of electron-bunch shaping methods based on bounded external electromagnetic fields or via interactions with the self-generated velocity and radiation fields.

中文翻译：

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电子直线加速器中的束成形

现代电子直线加速器通常设计用于产生以其宏观系综平均矩为特征的平滑束团分布。然而，越来越多的加速器应用要求对光束分布进行更精细的控制，例如要求其沿一个坐标的投影具有特定的形状。最终，在单粒子水平上控制光束分布可以为加速器科学带来新的机遇。这篇综述讨论了在“介观”尺度上控制电子束分布的最新进展，重点是塑造电子束或引入某些应用所需的复杂相关性。本综述强调了基于有界外部电磁场或通过与自生速度和辐射场相互作用的电子束成形方法的实验和理论发展。