论文标题
通过光学周期束火车对非常高的梯度等离子韦克菲尔德加速器的共振激发
Resonant excitation of very high gradient plasma wakefield accelerators by optical-period bunch trains
论文作者
论文摘要
使用周期性电子束束列火车在准非线性（QNL）方向上共鸣，激发了等离子体的血浆Wakefields，比使用单个，更高的充电束具有明显的优势。 QNL状态中的谐振激发可以使用非常低的发射光束产生等离子体电子井喷，每个脉冲电荷较小：局部密度扰动极为非线性，可实现总的稀疏性，但在等离子体频率下等离子体电子的谐振响应。这样的脉冲序列与等离子周期相等的脉冲序列可以通过反向自由电子激光束产生。为了通过几微米的激光波长实现共振，使用了高血浆密度，并且有可能获得极大的韦克场振幅，用于Facet-II参数接近1电视/m。在本文中，我们使用粒子中的模拟来研究血浆响应，束调节的演变以及遇到的不稳定性，这些响应是在使用束束方案以共鸣的浓度激发密集等离子体中的波动时会产生的。
Using a periodic electron beam bunch train to resonantly excite plasma wakefields in the quasi-nonlinear (QNL) regime has distinct advantages over employing a single, higher charge bunch. Resonant excitation in the QNL regime can produce plasma electron blowout using very low emittance beams with a small charge per pulse: the local density perturbation is extremely nonlinear, achieving total rarefaction, yet the resonant response of the plasma electrons at the plasma frequency is preserved. Such a pulse train, with inter-bunch spacing equal to the plasma period, can be produced via inverse free-electron laser bunching. To achieve resonance with a laser wavelength of a few microns, a high plasma density is used, with the attendant possibility of obtaining extremely large wakefield amplitude, near 1 TV/m for FACET-II parameters. In this article, we use particle-in-cell simulations to study the plasma response, the beam modulation evolution, and the instabilities encountered, that arise when using a bunching scheme to resonantly excite waves in a dense plasma.
