Danly C R, Day T H, Fittinghoff D N, Herrmann H, Izumi N, Kim Y H, Martinez J I, Merrill F E, Schmidt D W, Simpson R A, Volegov P L, Wilde C H
Los Alamos National Laboratory, Los Alamos, New Mexico 87544, USA.
Lawrence Livermore National Laboratory, Livermore, California 94550, USA.
Rev Sci Instrum. 2015 Apr;86(4):043503. doi: 10.1063/1.4918285.
Neutron and x-ray imaging provide critical information about the geometry and hydrodynamics of inertial confinement fusion implosions. However, existing diagnostics at Omega and the National Ignition Facility (NIF) cannot produce images in both neutrons and x-rays along the same line of sight. This leads to difficulty comparing these images, which capture different parts of the plasma geometry, for the asymmetric implosions seen in present experiments. Further, even when opposing port neutron and x-ray images are available, they use different detectors and cannot provide positive information about the relative positions of the neutron and x-ray sources. A technique has been demonstrated on implosions at Omega that can capture x-ray images along the same line of sight as the neutron images. The technique is described, and data from a set of experiments are presented, along with a discussion of techniques for coregistration of the various images. It is concluded that the technique is viable and could provide valuable information if implemented on NIF in the near future.
中子成像和X射线成像提供了关于惯性约束聚变内爆的几何结构和流体动力学的关键信息。然而，欧米伽激光装置（Omega）和国家点火装置（NIF）现有的诊断方法无法沿同一条视线同时生成中子和X射线图像。对于当前实验中观察到的不对称内爆，这导致难以比较这些捕捉到等离子体几何结构不同部分的图像。此外，即使有相对端口的中子和X射线图像，它们使用的是不同的探测器，并且无法提供关于中子源和X射线源相对位置的有效信息。一种技术已在欧米伽激光装置的内爆实验中得到验证，该技术能够沿与中子图像相同的视线捕捉X射线图像。本文描述了该技术，并给出了一组实验的数据，同时讨论了各种图像配准的技术。得出的结论是，该技术是可行的，如果在不久的将来在国家点火装置上实施，可能会提供有价值的信息。
