德国电子同步加速器DESY的Maier, A. R.团队研究了激光等离子体电子束的主动能量压缩。这一研究成果发表在2025年4月9日出版的《自然》杂志上。

提供高质量相对论电子束的射频（RF）加速器是实现许多科学领域以及工业和医学应用的重要资源。二十年前，支持比现代射频腔提供的电场高几个数量级的激光等离子体加速器首次产生了准单能电子束。从那时起，仅从厘米长的等离子体中就证明了千兆电子伏特（GeV）束能量和竞争性束特性的高亮度电子束，这比基于射频腔的加速器所需的数百米有很大的优势。然而，尽管取得了相当大的进展，但相对较大的能量扩散和光束能量的波动（抖动）仍然有效地阻止了激光等离子体加速器推动现实世界的应用。

研究组报告了使用主动能量压缩产生激光等离子体电子束，其性能迄今为止仅与现代基于射频的加速器相关。使用磁性chicane，电子束首先纵向拉伸以压印能量相关性，然后用有源RF腔去除。由此产生的能量扩散和能量抖动降低了一个数量级以上，低于permille水平，符合现代同步加速器的验收标准，从而为紧凑型存储环注入器和其他应用开辟了道路。

附：英文原文

Title: Active energy compression of a laser-plasma electron beam

Author: Winkler, P., Trunk, M., Hbner, L., Martinez de la Ossa, A., Jalas, S., Kirchen, M., Agapov, I., Antipov, S. A., Brinkmann, R., Eichner, T., Ferran Pousa, A., Hlsenbusch, T., Palmer, G., Schnepp, M., Schubert, K., Thvenet, M., Walker, P. A., Werle, C., Leemans, W. P., Maier, A. R.

Issue&Volume: 2025-04-09

Abstract: Radio-frequency (RF) accelerators providing high-quality relativistic electron beams are an important resource enabling many areas of science, as well as industrial and medical applications. Two decades ago, laser-plasma accelerators1 that support orders of magnitude higher electric fields than those provided by modern RF cavities produced quasi-monoenergetic electron beams for the first time2,3,4. Since then, high-brightness electron beams at gigaelectronvolt (GeV) beam energy and competitive beam properties have been demonstrated from only centimetre-long plasmas5,6,7,8,9, a substantial advantage over the hundreds of metres required by RF-cavity-based accelerators. However, despite the considerable progress, the comparably large energy spread and the fluctuation (jitter) in beam energy still effectively prevent laser-plasma accelerators from driving real-world applications. Here we report the generation of a laser-plasma electron beam using active energy compression, resulting in a performance so far only associated with modern RF-based accelerators. Using a magnetic chicane, the electron bunch is first stretched longitudinally to imprint an energy correlation, which is then removed with an active RF cavity. The resulting energy spread and energy jitter are reduced by more than an order of magnitude to below the permille level, meeting the acceptance criteria of a modern synchrotron, thereby opening the path to a compact storage ring injector and other applications.

DOI: 10.1038/s41586-025-08772-y

Source: https://www.nature.com/articles/s41586-025-08772-y