Surface acceleration of fast electrons with relativistic self-focusing in preformed plasma
Surface acceleration of fast electrons with relativistic self-focusing in preformed plasma
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DOI：
10.1103/physrevlett.97.095004
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发表时间：
2006-09-01
影响因子：
8.6
通讯作者：
Tanaka, K. A.
中科院分区：
文献类型：
--
作者：
Habara, H.;Adumi, K.;Tanaka, K. A.
本文报道了强激光与等离子体相互作用中快电子表面加速的观测结果。当预成型等离子体出现在固体靶前时，激光强度较高，快电子的发射方向从激光方向和镜面方向变为靶面方向。这种特征可能是由于沿靶表面形成了一个强的静态磁场，该磁场沿着靶表面捕获并保持快速电子在表面上。在我们的实验中，由于等离子体中的相对论自聚焦而引起的激光强度的增加对这种形成起着重要的作用。磁场的强度是由电子的弯曲角度计算的，导致激光磁场的百分之几十，这与二维粒子-细胞计算吻合得很好。强的表面电流解释了锥引导快速点火器实验上的高转换效率。
We report an observation of surface acceleration of fast electrons in intense laser-plasma interactions. When a preformed plasma is presented in front of a solid target with a higher laser intensity, the emission direction of fast electrons is changed to the target surface direction from the laser and specular directions. This feature could be caused by the formation of a strong static magnetic field along the target surface which traps and holds fast electrons on the surface. In our experiment, the increase in the laser intensity due to relativistic self-focusing in plasma plays an important role for the formation. The strength of the magnetic field is calculated from the bent angle of the electrons, resulting in tens of percent of laser magnetic field, which agrees well with a two-dimensional particle-in-cell calculation. The strong surface current explains the high conversion efficiency on the cone-guided fast ignitor experiments.