High efficiency tapered free-electron lasers with a prebunched electron beam
High efficiency tapered free-electron lasers with a prebunched electron beam
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DOI：
10.1103/physrevaccelbeams.20.110701
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发表时间：
2017-11
影响因子：
1.7
通讯作者：
C. Emma;N. Sudar;P. Musumeci;A. Urbanowicz;C. Pellegrini
中科院分区：
文献类型：
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作者：
C. Emma;N. Sudar;P. Musumeci;A. Urbanowicz;C. Pellegrini
本文分析了高增益、高效率的锥形自由电子激光放大器。简单的比例法则推导出的峰值输出功率和提取效率，并使用一维模拟验证。这些研究提供了有用的解析表达式，突出了系统的初始条件，即初始电子束聚束和输入种子辐射的精细控制所带来的好处。当包含时间相关效应时，已知边带不稳定性限制由于粒子脱陷引起的辐射放大。我们讨论了两种不同的方法，以减轻边带增长通过1-D时间相关的模拟。我们发现，一个更积极的锥度，使强大的预聚束和调制的共振条件都是有效的方法来抑制边带不稳定性的增长率。
In this paper we analyze the high gain, high efficiency tapered free-electron laser amplifier with a prebunched electron beam. Simple scaling laws are derived for the peak output power and extraction efficiency and verified using 1D simulations. These studies provide useful analytical expressions which highlight the benefits resulting from fine control of the initial conditions of the system, namely the initial electron beam bunching and input seed radiation. When time-dependent effects are included, the sideband instability is known to limit the radiation amplification due to particle detrapping. We discuss two different approaches to mitigate the sideband growth via 1-D time dependent simulations. We find that a more aggressive taper enabled by strong prebunching and a modulation of the resonance condition are both effective methods for suppressing the sideband instability growth rate.