Intensity-dependent resonance absorption in relativistic laser-plasma interaction
Intensity-dependent resonance absorption in relativistic laser-plasma interaction
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DOI：
10.1063/1.2397580
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发表时间：
2006-12
影响因子：
2.2
通讯作者：
Hui Xu;Z. Sheng;Jie Zhang;M. Yu
中科院分区：
文献类型：
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作者：
Hui Xu;Z. Sheng;Jie Zhang;M. Yu
通过细胞内粒子模拟研究了光强度对陡密度梯度等离子体中 p 偏振激光脉冲共振吸收的影响。对于给定的入射角和密度尺度长度，吸收率随着激光强度的增加而降低。这可以归因于局部等离子体频率的相对论性降低，从而导致驱动激光场与临界表面附近的激发电子等离子体波失谐。随着激光强度的进一步增加，吸收率开始增加，因为激光场现在可以进一步穿透等离子体达到更高的密度并驱动那里的密度空腔和峰值。结果，在不同位置发现了多重共振吸收。
The effect of light intensity on resonance absorption of p-polarization laser pulses in plasma with steep density gradients is studied by particle-in-cell simulations. For given incident angle and density scale length, the absorption rate decreases with an increase of the laser intensity. This can be attributed to a relativistic reduction of the local plasma frequency and thus detuning of the driving laser field from the excited electron plasma waves near the critical surface. With a further increase of the laser intensity, the absorption rate begins to increase since the laser field can now further penetrate into the plasma up to higher densities and drive density cavities and peaks there. As a result, multiple-resonant absorption is found at different locations.