论文标题
激光Wakefield加速器中的非线性等离子体波长尺度
Nonlinear plasma wavelength scalings in a laser wakefield accelerator
论文作者
论文摘要
激光Wakefield加速度依赖于由于强烈激光脉冲的浮动力引起的血浆波的激发。然而，在激光之后，几乎没有在实验中直接研究了血浆波序列。在这里，我们将少量的周期阴影图与干涉仪结合使用来量化GEV尺度加速器密度范围内激光激发的等离子体波，即几个1E18 cm-3。虽然分析模型表明非线性等离子体波长与峰电势A_0之间具有明显的依赖性，但我们的研究表明，分析模型仅适用于驱动器强度A_0 <= 1。实验数据和系统的粒子中模拟表明，血浆波序列的非线性延长不仅取决于激光峰强度，而且还取决于焦点的腰围。
Laser wakefield acceleration relies on the excitation of a plasma wave due to the ponderomotive force of an intense laser pulse. However, plasma wave trains in the wake of the laser have scarcely been studied directly in experiments. Here we use few-cycle shadowgraphy in conjunction with interferometry to quantify plasma waves excited by the laser within the density range of GeV-scale accelerators, i.e. a few 1e18 cm-3. While analytical models suggest a clear dependency between the non-linear plasma wavelength and the peak potential a_0, our study shows that the analytical models are only accurate for driver strength a_0<=1. Experimental data and systematic particle-in-cell simulations reveal that nonlinear lengthening of plasma wave train depends not solely on the laser peak intensity but also on the waist of the focal spot.
