Active longitudinal beam optics can help FEL facilities achieve cutting edge performance by optimizing the beam to: produce multi-color pulses, suppress caustics, or support attosecond lasing. As the next generation of superconducting accelerators comes online, there is a need to find new elements which can both operate at high beam power and which offer multiplexing capabilities at Mhz repetition rate. Laser heater shaping promises to satisfy both criteria by imparting a programmable slice-energy spread on a shot-by-shot basis. We use a simple kinetic analysis to show how control of the slice energy spread translates into control of the bunch current profile, and then we present a collection of start-to-end simulations at LCLS-II in order to illustrate the technique.
Coherent collective amplification of terahertz microbunching seeded by laser frequency beating in relativistic electron beams
Shanghai Advanced Research Institute, Chinese Academy of Sciences（中国科学院上海高等研究院）；Extreme Light Infrastructure – Nuclear Physics (ELI-NP), Horia Hulubei National Institute for R&D in Physics and Nuclear Engineering (IFIN-HH)（极光大设施-核物理（ELI-NP），霍里亚·胡卢贝伊国家物理与核工程研发研究所（IFIN-HH））
Bayesian Optimization of Laser-Wakefield Acceleration via Spectral Pulse Shaping
Lawrence Livermore National Laboratory（劳伦斯利弗莫尔国家实验室）；Lawrence Berkeley National Laboratory（劳伦斯伯克利国家实验室）；Portland State University（波特兰州立大学）；Department of Electrical and Computer Engineering, Colorado State University（科罗拉多州立大学电气与计算机工程系）；University of California, Berkeley（加州大学伯克利分校）
Spatiotemporal shaping of attosecond X-rays with time-dependent orbital angular momentum
Shanghai Institute of Applied Physics, Chinese Academy of Sciences（中国科学院上海应用物理研究所）；University of Chinese Academy of Sciences（中国科学院大学）；European XFEL（欧洲XFEL自由电子激光实验室）；Deutsches Elektronen-Synchrotron DESY（德国电子同步辐射研究所）；Shanghai Advanced Research Institute, Chinese Academy of Sciences（中国科学院上海高级研究院）
