基于光学干涉及层析技术构建ICF靶丸D/T 层三维密度场信息的研究

项目名称： 基于光学干涉及层析技术构建ICF靶丸D/T 层三维密度场信息的研究

项目编号： No.11275172

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 数理科学和化学

项目作者： 杨甬英

作者单位： 浙江大学

项目金额： 80万元

中文摘要： 惯性约束聚变（ICF）中，靶丸中氘氚 (D/T)燃料密度分布的控制和检测是实现成功点火的重要参数。本项目基于光学干涉及层析技术实现ICF靶丸D/T层空间三维密度场信息重构。首先针对微球尺度及出射波前畸变的情况，创新性地提出了微球密度分布信息获取的补偿会聚光优化光学系统建模，实现出射波前畸变最小化及高灵敏度。将研究一个共路抗干扰、紧凑适于旋转投影采样的二维交叉光栅与四窗口空间滤波器组成的横向剪切干涉系统，通过傅里叶光学信息处理及差分Zernike多项式拟合研究重构波前信息。最后为获取微球空间三维密度场，利用光学层析技术依次将其每个截面上各个投影角度数据提取后分别进行代数迭代法ART重构建模，得到不同截面上二维折射率分布。同时针对微球检测条件使投影角度受限情况，对ART算法进行修改，提高算法精度和收敛速度。该研究可为我国ICF工程、高超声速空气动力学密度场信息检测提供重要的研究基础。

中文关键词： ICF冷冻靶；四波前横向剪切干涉；层析技术；折射率场重构；随机编码混合光栅

英文摘要： In the experiment of inertial confinement fusion (ICF), the controlling and measurement of DT layer's density distribution in cryogenic targets plays an important role in successful ignition. This project will achieve reconstruction of three-dimensional density field of the DT layer inside ICF cryogenic targets on the basis of optical interferometry and tomography. Firstly, in accordance with the tiny size of cryogenic targets and wavefront distortion of the output beam, an innovative optical system for obtaining density distribution information from cryogenic targets is proposed, which applies optimized compensatory convergent-beam to realize minimization of output beam's wavefront distortion and high sensitivity. Moreover, a lateral shearing interferometer consisting of two-dimensional cross grating and four-window spatial filter is presented, which is designed to be common-path anti-disturbance and structurally compact for the purpose of rotational sampling on different projection angles. Also, using methods like Fourier optical information processing and differential Zernike polynomial fitting, the wavefront information of output beams can be obtained from lateral shearing interferograms. Finally, with the projection data on all projection angles of different cross-sections, we are capable of reconstructing

英文关键词： ICF cryogenic targets；Quadriwave lateral shearing interferometry；Tomography；Refractive index filed reconstruction；Randomly encoded hybrid grating