Three-dimensional hard X-ray imaging using coded penumbral camera

近年来，利用超短强激光脉冲进行激光核聚变和激光与物质相互作用的研究成为热点。硬X射线（高于10keV）成像是超短强激光脉冲等离子体诊断的重要课题。迄今为止，半影成像已被证明是硬X射线和中子等穿透辐射成像的强大技术。半影成像的局限性在于对半影图像中包含的噪声敏感和没有任何层析分辨率，为了克服上述局限性，我们提出了一种启发式的稳健重建方法和一种基于m序列的编码半影成像技术。通过使用编码半影孔径，可以获得具有高信噪比和断层分辨率的编码半影图像。本文的主要研究成果如下：（1）提出了一种启发式重建方法，该方法具有很好的鲁棒性 ...更多信息 并且容忍半影图像中包含的噪声。该方法已应用于激光等离子体密度的测量。研究结果已发表在Rev. Sci上。仪器(Ref. 4）。(2)提出了一种启发式盲重建方法。现在可以单独从半影图像重建源图像。该方法已应用于真实的激光聚变实验。研究结果发表在Rev. Sci上。仪器(Ref. 3）。(3)我们提出了一种启发式方法，从三个针孔图像的三维图像重建。该方法已应用于真实的激光聚变实验。研究结果已发表在Rev. Sci上。仪器(Ref. 1）。(4)提出了一种基于m序列的编码半影成像技术。通过使用编码半影孔径，可以获得具有高信噪比和断层分辨率的编码半影图像。结果将提交给Rev. Sci。仪器(5)本文定量地估计了m序列的层析分辨率，并指出精细采样可以提高层析分辨率。研究结果发表在Rev. Sci上。仪器(Ref. 2）。(6)提出了一种基于模拟退火的编码孔径图像三维重建启发式算法。实验结果表明，该方法可以明显改善重建的断层图像质量。针对启发式算法计算量大的问题，提出了一种快速算法。少

Recently, many researches have been focused on laser fusions and laser-matter interactions using ultra-short high intensity laser pulse. Imaging of hard x-ray (higher than 10keV) is an important issue for diagnostics of the plasma generated by the ultra-short high intensity laser pulse. To date, the penumbral imaging has been demonstrated as a powerful technique for imaging of penetrating radiations such as hard x-ray and neutrons. Limitations of the penumbral imaging are that it is sensitive to the noise contained in the penumbral images and it do not have any tomographic resolutions.In order to overcome above limitations, we proposed a heuristic method for robust reconstruction and a coded penumbral imaging technique based on a m-sequence. It is possible to obtain a coded penumbral image with high SN ratio and tomographic resolution by the use of coded penumbral apertures. The main results are summarized as following:(1) We proposed a heuristic reconstruction method, which is very ro … More bust and tolerant to the noise contained in the penumbral images. The method has been applied for measurements of laser-produced plasma density. The results have been published in Rev. Sci. Instrum. (Ref. 4).(2) We proposed a heuristic blind reconstruction method. It is now possible to reconstruct the source image from the penumbral images alone. The proposed method has also been applied to real laser fusion experiments. The results have published in Rev. Sci. Instrum. (Ref. 3).(3) We proposed a heuristic method for 3D image reconstructions from three pinhole images. The proposed method has also been applied to real laser fusion experiments. The results have been published in Rev. Sci. Instrum. (Ref. 1).(4) We newly proposed a coded penumbral imaging technique based on m-sequence. It is possible to obtain a coded penumbral image with high SN ratio and tomographic resolution by the use of coded penumbral apertures. The results will be submitted to Rev. Sci. Instrum.(5) We quantitatively estimated the tomographic resolution of m-sequence and shown that the tomographic resolution can be improved by use of the fine sampling. The results have published in Rev. Sci. Instrum. (Ref. 2).(6) We proposed a new heuristic algorithm for three-dimensional image reconstruction from coded aperture images based on simulated annealing (SA). It has been shown that the reconstructed tomographic images can be significantly improved by using the proposed method. We also proposed a fast algorithm to reduce the large computation cost of the heuristic algorithm. Less