Nonlinear evolution of stimulated Raman scattering near the quarter-critical density
Nonlinear evolution of stimulated Raman scattering near the quarter-critical density
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DOI：
10.1063/1.4921644
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发表时间：
2015-05
影响因子：
2.2
通讯作者：
C. Xiao;Z. J. Liu;Dong Wu;C. Zheng;Xiantu He
中科院分区：
文献类型：
--
作者：
C. Xiao;Z. J. Liu;Dong Wu;C. Zheng;Xiantu He
采用一维和二维粒子模拟方法研究了均匀等离子体中受激拉曼散射（SRS）在四分之一临界密度附近的非线性演化。在1D组态中，排除了两个等离子体衰变（TPD）不稳定性，系统演化为两个区域，其区别在于是否形成密度腔。在低温下，腔政权的特点是高吸收和低反射，并在高温下，由于粒子捕获的非线性频移制度，观察。此外，在二维模拟中SRS和TPD之间的竞争表明，非线性SRS确实在四分之一临界密度附近起着重要作用，其影响以前大多被忽略。
Nonlinear evolution of stimulated Raman scattering (SRS) near the quarter-critical density is studied using one-dimensional (1D) and two-dimensional (2D) particle-in-cell simulations in homogeneous plasmas. In 1D configuration, with two-plasmon decay (TPD) instability excluded, the system evolves into two regimes distinguished by whether density cavities have been formed or not. At low temperatures, a cavity regime characterised by high absorption and low reflection, and at high temperatures nonlinear frequency shift regime due to particle trapping, are observed. Furthermore, a competition between SRS and TPD in 2D simulations reveals that the nonlinear SRS does play a significant role near the quarter-critical density, whose influences were mostly neglected before.