截断可调等离子体通道中的电子再相位
Electron Rephasing in a Truncated Tunable Plasma Channel
- Weizmann Institute of Science（魏茨曼科学研究所）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
该研究通过实验和模拟表明，在截断等离子体通道中改变通道长度可调控电子束的再相位与加速，从而控制电子能谱形态，为激光尾场加速提供了关键控制参数。
AI中文摘要：
我们报道了使用50太瓦激光脉冲在由轴抛物面聚焦加热脉冲产生的预成型等离子体通道中引导，加速了能量高达1.5吉电子伏的稳定电子束。改变通道长度会改变通道末端之外的等离子体密度，并产生不同的电子能谱。短通道在截断后导致气泡尺寸大幅减小，仅使部分电子束处于加速相位，从而产生准单能峰。对于在目标密度下降斜坡附近结束的较长通道，较小的密度增加会使更大比例的束流重新相位并进一步加速，产生连续的高电荷能谱。流体动力学和粒子单元模拟再现了观察到的能谱演化。综合测量和模拟，确定通道长度是引导激光尾场加速中的关键控制参数。
英文摘要：
We report the acceleration of stable electron beams with energies up to 1.5 GeV using a 50 TW laser pulse guided in a preformed plasma channel generated by an axiparabola-focused heater pulse. Varying the channel length changes the plasma density beyond the channel end and produces distinct electron spectra. A short channel causes a large decrease in bubble size after the truncated channel, leaving only part of the electron bunch in the accelerating phase and resulting in a quasi-monoenergetic peak. For a longer channel ending near the target density down-ramp, the smaller density increase rephases and further accelerates a larger fraction of the bunch, producing a continuous high-charge spectrum. Hydrodynamic and particle-in-cell simulations reproduce the observed spectral evolution. Together, the measurements and simulations identify channel length as a key control parameter in guided laser-wakefield acceleration.
