Sudar N, Musumeci P, Gadjev I, Sakai Y, Fabbri S, Polyanskiy M, Pogorelsky I, Fedurin M, Swinson C, Kusche K, Babzien M, Palmer M
Department of Physics and Astronomy, Particle Beam Physics Laboratory, University of California, Los Angeles, California 90095, USA.
Accelerator Test Facility, Brookhaven National Laboratory, Upton, New York 11973, USA.
Phys Rev Lett. 2018 Mar 16;120(11):114802. doi: 10.1103/PhysRevLett.120.114802.
We present results of an experiment showing the first successful demonstration of a cascaded microbunching scheme. Two modulator-chicane prebunchers arranged in series and a high power mid-IR laser seed are used to modulate a 52 MeV electron beam into a train of sharp microbunches phase locked to the external drive laser. This configuration is shown to greatly improve matching of the beam into the small longitudinal phase space acceptance of short-wavelength accelerators. We demonstrate trapping of nearly all (96%) of the electrons in a strongly tapered inverse free-electron laser accelerator, with an order-of-magnitude reduction in injection losses compared to the classical single-buncher scheme. These results represent a critical advance in laser-based longitudinal phase space manipulations and find application in high gradient advanced acceleration as well as in high peak and average power coherent radiation sources.
我们展示了一项实验的结果，该实验首次成功演示了一种级联微聚束方案。使用两个串联排列的调制器-弯道预聚束器和一个高功率中红外激光种子，将52兆电子伏特的电子束调制为一串与外部驱动激光锁相的尖锐微聚束。结果表明，这种配置大大改善了束流与短波长加速器小纵向相空间接受度的匹配。我们证明，在强渐变逆自由电子激光加速器中，几乎所有（96%）的电子都能被捕获，与传统的单聚束器方案相比，注入损失降低了一个数量级。这些结果代表了基于激光的纵向相空间操纵的关键进展，并在高梯度先进加速以及高峰值和平均功率相干辐射源中得到应用。
