激光腔靶耦合二维辐射输运数值模拟

间接驱动激光聚变过程中,黑腔内物质处于非局域热动平衡(non-LTE)状态,而且辐射传输具有非平衡、各向异性等特点。为了精确描述黑腔辐射场的演化及其与物质的相互作用,最新研制的激光聚变二维总体LARED集成程序,基于non-LTE的多群辐射输运建模,首次实现了激光黑腔靶实验的全过程数值模拟。数值结果表明,辐射输运计算较好地反映了黑腔辐射场均匀性变化,腔壁光斑区与非光斑区X光发射强度比与实验测量值接近,靶丸压缩形状与实验图像定性一致。

Two-dimensional radiative transfer calculations of the laser-target hohlraum

High non-LTE issue of ionization and radiative transfer are important physical characteristics of the laser-target hohlraum. Detailed multi-group transport approximation under non-LTE atomic physics is necessary for precisely describing radiation transfer and its interaction with matter. Using the recently developed LARED-integration code, we have accomplished multi-group radiative transfer calculations of the laser-target experimental hohlraum in 2D. Numerical results reflect the radiative illumination ununiformity inside the hohlraum. The ratio of X-ray intensity of the laser spot versus other regions along the gold wall agrees well with that of the experimental result, meanwhile the measured and simulated fuel shape resembles each other closely.