Merrill F E, Danly C R, Izumi N, Jedlovec D, Fittinghoff D N, Grim G P, Pak A, Park H-S, Volegov P L, Wilde C H
Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
Livermore National Laboratory, Livermore, California 94551, USA.
Rev Sci Instrum. 2014 Nov;85(11):11E614. doi: 10.1063/1.4891101.
Neutron and x-ray images are collected at the National Ignition Facility (NIF) to measure the size and shape of inertial confinement fusion implosions. The x-ray images provide a measure of the size and shape of the hot region of the deuterium-tritium fuel while the neutron images provide a measure of the size and shape of the burning plasma. Although these two types of images are collected simultaneously, they are not collected along the same line of sight (LOS). One 14 MeV neutron image is collected on the NIF equator, and two x-ray images are collected along the polar axis and nearly perpendicular to the neutron imaging line of sight on the equator. Both measurements use pinhole apertures to form the images, but existing x-ray imaging provides time-resolved measurements while the neutron images are time-integrated. Detailed comparisons of the x-ray and neutron images can provide information on the fuel assembly, but these studies have been limited because the implosions are not azimuthally symmetric and the images are collected along different LOS. We have developed a conceptual design of a time-integrated x-ray imaging system that could be added to the existing neutron imaging LOS. This new system would allow these detailed studies, providing important information on the fuel assembly of future implosions. Here we present this conceptual design and the expected performance characteristics.
在国家点火装置（NIF）收集中子和X射线图像，以测量惯性约束聚变内爆的尺寸和形状。X射线图像提供了氘 - 氚燃料热区尺寸和形状的测量结果，而中子图像提供了燃烧等离子体尺寸和形状的测量结果。尽管这两种类型的图像是同时收集的，但它们不是沿同一条视线（LOS）收集的。在NIF赤道上收集一张14兆电子伏特的中子图像，沿极轴并几乎垂直于赤道上中子成像视线收集两张X射线图像。这两种测量都使用针孔孔径来形成图像，但现有的X射线成像提供时间分辨测量，而中子图像是时间积分的。X射线和中子图像的详细比较可以提供有关燃料组件的信息，但这些研究受到限制，因为内爆不是方位对称的，并且图像是沿不同的视线收集的。我们已经开发了一种时间积分X射线成像系统的概念设计，可以添加到现有的中子成像视线上。这个新系统将允许进行这些详细研究，提供有关未来内爆燃料组件的重要信息。在这里，我们展示了这个概念设计和预期的性能特征。
