Impact of temperature-velocity distribution on fusion neutron peak shape
Impact of temperature-velocity distribution on fusion neutron peak shape
复制标题
温度-速度分布对聚变中子峰形的影响
DOI：
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发表时间：
2016
期刊：
影响因子：
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通讯作者：
D. Munro
中科院分区：
文献类型：
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作者：
D. Munro
14 MeV DT和2.45 MeV DD聚变中子谱线的多普勒展宽一直是我们测量燃烧等离子体温度的最佳方法。在国家点火装置（NIF），产量足够高，我们的中子光谱仪足够精确，我们可以看到峰形状的更精细的细节。例如，我们可以测量由于等离子体的大块运动而引起的峰值位移，并且我们可以看到由燃烧过程中温度和流体速度的变化引起的峰值的非热展宽、倾斜和峰度的迹象。我们还可以区分几条视线之间的光谱差异。本文将回顾核聚变中子线形的理论，展示NIF数据中的非高斯线形和方向变化的例子，并描述我们在内爆辐射-流体动力学模拟中看到的详细光谱形状。
Doppler broadening of the 14 MeV DT and 2.45 MeV DD fusion neutron lines has long been our best measure of temperature in a burning plasma. At the National Ignition Facility (NIF), yields are high enough and our neutron spectrometers accurate enough that we see finer details of the peak shape. For example, we can measure the shift of the peak due to the bulk motion of the plasma, and we see indications of non-thermal broadening, skew, and kurtosis of the peak caused by the variations of temperature and fluid velocity during burn. We can also distinguish spectral differences among several lines of sight. This paper will review the theory of fusion neutron line shape, show examples of non-Gaussian line shapes and directional variations in NIF data, and describe detailed spectral shapes we see in radiation-hydrodynamics simulations of implosions.