论文标题
电子束驱动的等离子体唤醒的耗散
Dissipation of electron-beam-driven plasma wakes
论文作者
论文摘要
米尺度的等离子体韦克菲尔德加速器已将能量增益接近10 gigaelectronvolts到单个纳米-Coulomb Electron束。但是，要达到有用的平均电流，必须在镜头之间有效地将驾驶员沉积到尾流的巨大能量密度。然而，醒来的机制将其能量耗散到周围的血浆中仍然知之甚少。在这里，我们报告了PS时间分辨，放牧 - 角度的光学阴影测量值以及从破碎的唤醒中出现的离子通道的大规模粒子模拟，这些尾流来自SLAC LINAC从SLAC LINAC中产生的，以弱锂等离子产生。测量结果表明，通道边界在纳秒超过一百万个元位时径向扩展。模拟表明，原始唤醒向外推动的离子和电子载有90％的能量，通过围绕中性锂的影响离子化来推动这种扩展。结果为理解多GEV等离子体加速器的全球热力学提供了一个基础，这些热力学是其对需要高平均光束电流的应用的可行性的基础。
Metre-scale plasma wakefield accelerators have imparted energy gain approaching 10 gigaelectronvolts to single nano-Coulomb electron bunches. To reach useful average currents, however, the enormous energy density that the driver deposits into the wake must be removed efficiently between shots. Yet mechanisms by which wakes dissipate their energy into surrounding plasma remain poorly understood. Here, we report ps-time-resolved, grazing-angle optical shadowgraphic measurements and large-scale particle-in-cell simulations of ion channels emerging from broken wakes that electron bunches from the SLAC linac generate in tenuous lithium plasma. Measurements show the channel boundary expands radially at 1 million metres-per-second for over a nanosecond. Simulations show that ions and electrons that the original wake propels outward, carrying 90 percent of its energy, drive this expansion by impact-ionizing surrounding neutral lithium. The results provide a basis for understanding global thermodynamics of multi-GeV plasma accelerators, which underlie their viability for applications demanding high average beam current.
