论文标题
优化和稳定kilohertz激光 - 血浆加速器
Optimization and stabilization of a kilohertz laser-plasma accelerator
论文作者
论文摘要
最近已证明以kilohertz重复速率的激光血浆加速度在两个不同的方向上起作用，脉冲长度为30 fs或3.5 fs。现在，我们报告了一项系统的研究，其中通过连续调整激光光谱带宽来研究大量的脉冲持续时间和等离子体密度。实际上，可以区分两个LPA过程，其中最高质量的光束具有5.4 PC电荷，并且在2-2.5 MEV处达到峰值的光谱，而短脉冲在中等等离子体密度下传播。通过粒子中的模拟，可以彻底解释两个不同的加速过程。最后，我们继续显示LPA加速器连续稳定运行的结果，累积了超过$ \ MATHRM {18 \ times10^6} $连续拍摄，并具有2.6 PC充电，峰值2.5 MEV频谱。通过PIC模拟对激光驱动器能量的影响的参数研究强调，由于微尺度密度梯度注入，获得了前所未有的稳定性。总之，这些结果代表了以kilohertz的重复速率迈出稳定激光型抛光电子束的重要步骤。
Laser plasma acceleration at kilohertz repetition rate has recently been shown to work in two different regimes, with pulse lengths of either 30 fs or 3.5 fs. We now report on a systematic study in which a large range of pulse durations and plasma densities were investigated through continuous tuning of the laser spectral bandwidth. Indeed, two LPA processes can be distinguished, where beams of the highest quality, with 5.4 pC charge and a spectrum peaked at 2-2.5 MeV are obtained with short pulses propagating in moderate plasma densities. Through Particle-in-Cell simulations the two different acceleration processes are thoroughly explained. Finally, we proceed to show the results of a 5-hour continuous and stable run of our LPA accelerator accumulating more than $\mathrm{18\times10^6}$ consecutive shots, with 2.6 pC charge and peaked 2.5 MeV spectrum. A parametric study of the influence of the laser driver energy through PIC simulations underlines that this unprecedented stability was obtained thanks to micro-scale density gradient injection. Together, these results represent an important step towards stable laser-plasma accelerated electron beams at kilohertz repetition rate.
