Simple model of energy deposition by suprathermal electrons in laser-irradiated targets
Simple model of energy deposition by suprathermal electrons in laser-irradiated targets
复制标题
激光照射靶中超热电子能量沉积的简单模型
DOI：
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发表时间：
1981
期刊：
影响因子：
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通讯作者：
R. Kidder
中科院分区：
文献类型：
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作者：
R. Harrach;R. Kidder
用基于斯宾塞电子输运计算的模型描述了超热电子在激光照射目标中的能量沉积（预热）。在曲线范围内，找到了比能量沉积${\mathcal{E}}_{\ mathm {deep}}(\frac{J}{g})$和超越给定深度传输能量的分数$f$的近似解析解和数值解。给出了金、铝、碳等均质靶的计算实例。简要讨论了该模型在多层复合目标处理中的应用。这些结果的参数依赖性表明，迄今为止最重要的参数是热电子或超热电子的源温度${T}_{h}$。该模型的预测结果与钕玻璃激光脉冲辐照金盘和铝盘在${10}^{15}$ W/${\ mathm {cm}}^{2}$能级上的实验数据吻合较好。在理论与数据的比较中包含了基于其他几个简单模型和实验的大型代码模拟的这些实验的预测。未来精确测量${T}_{h}$的铝盘实验可以为这些理论提供一个灵敏的检验。
Energy deposition (preheat) by suprathermal electrons in laser-irradiated targets is described using a model based on Spencer's electron transport calculation. Approximate analytical, as well as numerical, solutions are found for the specific energy deposition ${\mathcal{E}}_{\mathrm{dep}}(\frac{J}{g})$ and fraction $f$ of energy transmitted beyond a given depth, measured in curvilinear ranges. Example calculations are presented for homogeneous targets of gold, aluminum, and carbon. The application of the model to treat multilayer composite targets is briefly considered. The parametric dependence of these results reveal that the most significant parameter by far is the source temperature ${T}_{h}$ of the hot or suprathermal electrons. The predictions of the preheat model are shown to be in good agreement with experimental data on gold and aluminum disks irradiated by Nd-glass laser pulses at the ${10}^{15}$ W/${\mathrm{cm}}^{2}$ level. Included in the theory-data comparison are predictions for these experiments based on several other simple models and large code simulations of the experiments. Future aluminum disk experiments in which ${T}_{h}$ is accurately measured could provide a sensitive test for the theories.