Multibeam laser-plasma interaction at the Gekko XII laser facility in conditions relevant for direct-drive inertial confinement fusion
Multibeam laser-plasma interaction at the Gekko XII laser facility in conditions relevant for direct-drive inertial confinement fusion
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DOI：
10.1017/hpl.2023.13
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发表时间：
2023-02-20
影响因子：
4.8
通讯作者：
Gizzi, L. A.
中科院分区：
文献类型：
--
作者：
Cristoforetti, G.;Koester, P.;Gizzi, L. A.
激光等离子体相互作用和热电子已在与直接驱动惯性约束聚变相关的激光照射条件下进行了详细表征。该实验是在 Gekko XII 激光设备的多光束平面目标几何结构中进行的，强度约为 3 x 10(15) W/cm(2)。实验数据表明，温度为20-50 keV、转换效率eta < 1%的高能电子主要是由双等离子体衰变（TPD）驱动的电子等离子体波阻尼产生的。受激拉曼散射 (SRS) 在接近阈值的生长状态下观察到，产生约 0.01% 的反射率，并通过解释独立散斑中对流生长的分析模型得到了很好的描述。实验表明，TPD和SRS均由多光束共同驱动，比单光束激光强度驱动的生长更加旺盛。
Laser-plasma interaction and hot electrons have been characterized in detail in laser irradiation conditions relevant for direct-drive inertial confinement fusion. The experiment was carried out at the Gekko XII laser facility in multibeam planar target geometry at an intensity of approximately 3 x 10(15) W/cm(2). Experimental data suggest that high-energy electrons, with temperatures of 20-50 keV and conversion efficiencies of eta < 1%, were mainly produced by the damping of electron plasma waves driven by two-plasmon decay (TPD). Stimulated Raman scattering (SRS) is observed in a near-threshold growth regime, producing a reflectivity of approximately 0.01%, and is well described by an analytical model accounting for the convective growth in independent speckles. The experiment reveals that both TPD and SRS are collectively driven by multiple beams, resulting in a more vigorous growth than that driven by single-beam laser intensity.