论文标题
毛细管排放血浆波导长度高达40厘米的径向密度和稳定性
Radial Density Profile and Stability of Capillary Discharge Plasma Waveguides of Lengths up to 40 Centimeters
论文作者
论文摘要
我们测量了直径为650 um至2 mm，长度为9至40 cm的毛细管排放波导的参数可重复性和径向电子密度谱。据我们所知，迄今为止，40厘米是最长的放电毛细血管血浆波导。对于> = = 10 GEV电子能量增益至关重要，在单个激光驱动的等离子体Wakefield加速度（LPA）阶段。波导参数变化的评估表明，它们的聚焦强度稳定且可再现至<0.2％，其平均轴上等离子体电子密度<1％。这些变化仅解释了迄今为止在实验中观察到的LPA电子束变化的一小部分。激光脉冲中心振荡的测量结果表明，径向通道的谱图升高的速度比抛物线寄生虫快，并且与磁动力学模拟结果非常吻合。我们表明，当脉冲大致与通道匹配时，非羟基贡献对高斯脉冲传播的影响可以忽略不计。但是，它们影响了不匹配的配置的脉冲传播，其中波导用作等离子体望远镜，以更改聚焦的激光脉冲斑点大小。
We measured the parameter reproducibility and radial electron density profile of capillary discharge waveguides with diameters of 650 um to 2 mm and lengths of 9 to 40 cm. To our knowledge, 40 cm is the longest discharge capillary plasma waveguide to date. This length is important for >= 10 GeV electron energy gain in a single laser driven plasma wakefield acceleration (LPA) stage. Evaluation of waveguide parameter variations showed that their focusing strength was stable and reproducible to <0.2% and their average on-axis plasma electron density to <1%. These variations explain only a small fraction of LPA electron bunch variations observed in experiments to date. Measurements of laser pulse centroid oscillations revealed that the radial channel profile rises faster than parabolic and are in excellent agreement with magneto-hydro-dynamic simulation results. We show that the effects of non-parabolic contributions on Gaussian pulse propagation were negligible when the pulse was approximately matched to the channel. However, they affected pulse propagation for a non-matched configuration in which the waveguide was used as a plasma telescope to change the focused laser pulse spot size.
