论文标题
研究兰登对刺激的向后拉曼和布里鲁因散射的效应
Investigation of Langdon effect on the stimulated backward Raman and Brillouin scattering
论文作者
论文摘要
在激光辐射的等离子体中，兰登效应使电子能量分布函数（EEDF）倾向于超级高斯分布，这对激光血浆不稳定性具有重要影响。在这项工作中，系统地研究了超级高斯EEDF对对流刺激的向后拉曼散射（SRS）和刺激的后向布里渊散射（SBS）的影响，以针对惯性限制融合（ICF）中的各种典型等离子体参数进行系统地研究。在峰值空间生长速率的变化趋势和散射光的相应波长的变化趋势下，发现了SR和SBS的不同行为。尤其是，详细分析了具有不同离子物种和同位素的等离子体中SBS的兰登效应，并首次提出了SBS与Supergaussian指数的峰值空间生长速率的变化趋势的参数边界。在某些血浆参数区域中，发现Langdon效应可以增强混合等离子体中的SBS，这可能会通过将低Z离子混合到高Z血浆中来减轻抑制SBS的改善。这些对Langdon对LPI的影响的理解将有助于更好地理解实验中SRS和SBS。
In a laser-irradiated plasma, the Langdon effect makes the electron energy distribution function (EEDF) tend to a super-Gaussian distribution, which has important influences on laser plasma instabilities. In this work, the influences of a super-Gaussian EEDF on the convective stimulated backward Raman scattering (SRS) and stimulated backward Brillouin scattering (SBS) are studied systematically for a wide range of typical plasma parameters in the inertial confinement fusion (ICF). Distinct behaviors are found for SRS and SBS in the variation trend of the peak spatial growth rate and the corresponding wavelength of the scattered light. Especially, the Langdon effect on the SBS in plasmas with different ion species and isotopes is analyzed in detail, and the parameter boundary for judging the variation trend of the peak spatial growth rate of SBS with the superGaussian exponent is presented for the first time. In certain plasma parameter region, it is found that the Langdon effect could enhance SBS in mixed plasma, which may attenuate the improvement in suppressing SBS by mixing low-Z ions into the high-Z plasma. These comprehension of Langdon effect on LPIs would contribute to a better understanding of SRS and SBS in experiments.
