Electron pulse train accelerated by a linearly polarized Laguerre–Gaussian laser beam
Electron pulse train accelerated by a linearly polarized Laguerre–Gaussian laser beam
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DOI：
10.1017/hpl.2022.37
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发表时间：
2022-11
影响因子：
4.8
通讯作者：
Yin Shi;D. Blackman;Ping Zhu;A. Arefiev
中科院分区：
文献类型：
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作者：
Yin Shi;D. Blackman;Ping Zhu;A. Arefiev
扭曲指数$l = -1$的线偏振拉盖尔-高斯（LP-LG）激光束的场结构与传统线偏振高斯光束的场结构有本质的区别。靠近LP-LG光束的轴线，纵向电场和磁场主导横向分量。这种结构提供了在真空中加速电子的诱人机会。利用三维细胞内粒子模拟表明，这种情况可以通过将LP-LG激光反射到具有急剧密度梯度的等离子体上来实现。仿真结果表明，600 TW的LP-LG激光束在反射过程中有效地向光束注入了电子。在激光轴附近注入的电子在纵向激光电场的作用下经历了长时间的纵向加速度。电子形成明显的单能束，发散角小。高能束的能量为0.29 GeV。捆包费用为6美元，期限约为270美元。散度角为${0.57}^{\circ}$ （10 mrad）。通过使用线偏振而不是圆偏振的拉盖尔-高斯光束，我们的方案更容易在高功率激光设备上实验证明电子加速。
Abstract A linearly polarized Laguerre–Gaussian (LP-LG) laser beam with a twist index $l = -1$ has field structure that fundamentally differs from the field structure of a conventional linearly polarized Gaussian beam. Close to the axis of the LP-LG beam, the longitudinal electric and magnetic fields dominate over the transverse components. This structure offers an attractive opportunity to accelerate electrons in vacuum. It is shown, using three-dimensional particle-in-cell simulations, that this scenario can be realized by reflecting an LP-LG laser off a plasma with a sharp density gradient. The simulations indicate that a 600 TW LP-LG laser beam effectively injects electrons into the beam during the reflection. The electrons that are injected close to the laser axis experience a prolonged longitudinal acceleration by the longitudinal laser electric field. The electrons form distinct monoenergetic bunches with a small divergence angle. The energy in the most energetic bunch is 0.29 GeV. The bunch charge is 6 pC and its duration is approximately $270$ as. The divergence angle is just ${0.57}^{\circ }$ (10 mrad). By using a linearly polarized rather than a circularly polarized Laguerre–Gaussian beam, our scheme makes it easier to demonstrate the electron acceleration experimentally at a high-power laser facility.