Study of fast electron generation using multi beam of LFEX-class laser
Study of fast electron generation using multi beam of LFEX-class laser
复制标题
利用LFEX级激光器多光束快速产生电子的研究
DOI：
10.1088/1742-6596/717/1/012037
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
and H. Nagatomo
中科院分区：
文献类型：
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作者：
M. Hata;H. Sakagami;T. Johzaki;Y. Sentoku;and H. Nagatomo
快速点火实现实验项目第一阶段（FIREX-I）正在大坂大学激光工程研究所进行。在这个项目中，四束集束高能拍瓦激光器（LFEX）正在运行。LFEX激光器提供了很大的多光束照射灵活性，可以按时间顺序排列脉冲，在空间上将它们分离在不同的光斑中，或者将它们聚焦在单个光斑中。本文采用二维相对论粒子模拟方法研究了高强度皮秒激光与等离子体相互作用中的双光束干涉效应。干涉引起表面扰动，这增强了激光吸收和低密度等离子体产生，增加了加速电子数和它们的斜率温度。与单束情况相比，双束干涉情况下的激光-电子能量转换效率更适合于快速点火（FI），但快速电子发散角的增加导致能量耦合降低。为了优化FI的目标设计，应该考虑这些干扰效应。
Fast Ignition Realization Experiment project phase-I (FIREX-I) is being performed at Institute of Laser Engineering, Osaka University. In this project, the four-beam bundled high-energy Petawatt laser (LFEX) is being operated. LFEX laser provides great multi-beam irradiation flexibility, with the possibility of arrange the pulses in temporal sequence, spatially separate them in distinct spots of focus them in a single spot. In this paper, we study the two-beam interference effects on high-intensity picosecond laser-plasma interaction (LPI) by twodimensional relativistic Particle-In-Cell simulations. The interference causes surface perturbation, which enhances laser absorption and underdense plasma generation, increasing the accelerated electron number and their slope temperature. The laser-to-electron energy conversion efficiency for two-beam interference case is suitable for Fast Ignition (FI) compared to the single beam case, but the increment of fast electron divergence leads to lower energy coupling. To optimize the target design for FI, these interference effects should be taken into consideration.