Jakobsson O, Hooker S M, Walczak R
John Adams Institute for Accelerator Science and Department of Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH, United Kingdom.
Phys Rev Lett. 2021 Oct 29;127(18):184801. doi: 10.1103/PhysRevLett.127.184801.
We describe a new approach for driving GeV-scale plasma accelerators with long laser pulses. We show that the temporal phase of a long, high-energy driving laser pulse can be modulated periodically by copropagating it with a low-amplitude plasma wave driven by a short, low-energy seed pulse. Compression of the modulated driver by a dispersive optic generates a train of short pulses suitable for resonantly driving a plasma accelerator. Modulation of the driver occurs via well-controlled linear processes, as confirmed by good agreement between particle-in-cell (PIC) simulations and an analytic model. PIC simulations demonstrate that a 1.7 J, 1 ps driver, and a 140 mJ, 40 fs seed pulse can accelerate electrons to energies of 0.65 GeV in a plasma channel with an axial density of 2.5×10^{17} cm^{-3}. This work opens a route to high repetition-rate, GeV-scale plasma accelerators driven by thin-disk lasers, which can provide joule-scale, picosecond-duration laser pulses at multikilohertz repetition rates and high wall-plug efficiencies.
我们描述了一种利用长激光脉冲驱动吉电子伏特（GeV）级等离子体加速器的新方法。我们表明，通过使长的高能驱动激光脉冲与由短的低能种子脉冲驱动的低振幅等离子体波共传播，可以周期性地调制其时间相位。通过色散光学器件对调制后的驱动脉冲进行压缩，会产生一系列适合共振驱动等离子体加速器的短脉冲。正如粒子模拟（PIC）与解析模型之间的良好一致性所证实的那样，驱动脉冲的调制是通过可控的线性过程发生的。PIC模拟表明，一个1.7焦耳、1皮秒的驱动脉冲和一个140毫焦耳、40飞秒的种子脉冲，能够在轴向密度为2.5×10¹⁷厘米⁻³的等离子体通道中将电子加速到0.65吉电子伏特的能量。这项工作为高重复率、GeV级的由薄盘激光器驱动的等离子体加速器开辟了一条道路，这种激光器能够以多千赫兹的重复率和高壁插效率提供焦耳级、皮秒持续时间的激光脉冲。
