Beyond the ponderomotive limit: Direct laser acceleration of relativistic electrons in sub-critical plasmas
Beyond the ponderomotive limit: Direct laser acceleration of relativistic electrons in sub-critical plasmas
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DOI：
10.1063/1.4946024
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发表时间：
2016-05-01
影响因子：
2.2
通讯作者：
Schollmeier, M.
中科院分区：
文献类型：
--
作者：
Arefiev, A. V.;Khudik, V. N.;Schollmeier, M.
我们研究了一个制度，在该制度中，线偏振激光脉冲相对论强度照射亚临界等离子体的时间远远长于特征电子的响应时间。在这种情况下，准静态横向和纵向电场在等离子体中形成稳态通道。这些相对较弱的场显著地改变了电子动力学。纵向电场减少了电子和波之间的纵向失相，导致来自脉冲的电子能量增益的增强。在这个制度中的能量增益最终是有限的，由在通道中的等离子体引起的波前的超光度。横向电场改变横向电子速度的振荡，使其保持反平行于激光电场，并导致显着的能量增益。能量增强伴随着垂直于驱动运动平面的显著振荡的发展，使得高能电子的轨迹是三维的。适当的电子注入到激光束中可以进一步提高电子能量增益。由AIP出版社出版。
We examine a regime in which a linearly polarized laser pulse with relativistic intensity irradiates a sub-critical plasma for much longer than the characteristic electron response time. A steady-state channel is formed in the plasma in this case with quasi-static transverse and longitudinal electric fields. These relatively weak fields significantly alter the electron dynamics. The longitudinal electric field reduces the longitudinal dephasing between the electron and the wave, leading to an enhancement of the electron energy gain from the pulse. The energy gain in this regime is ultimately limited by the superluminosity of the wave fronts induced by the plasma in the channel. The transverse electric field alters the oscillations of the transverse electron velocity, allowing it to remain anti-parallel to laser electric field and leading to a significant energy gain. The energy enhancement is accompanied by the development of significant oscillations perpendicular to the plane of the driven motion, making trajectories of energetic electrons three-dimensional. Proper electron injection into the laser beam can further boost the electron energy gain. Published by AIP Publishing.