Characteristics and improvement scheme of dark-field imaging of high energy electron radiography
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摘要: 基于EGS5与PARMELA模拟软件组成的高能电子成像系统，对暗场成像的模拟研究发现，通过调节光阑位置实现的暗场成像结果存在失真现象。针对该失真现象提出的改进方案，消除了暗场成像结果的失真。通过对40 MeV电子透射7~224 μm的铝样品开展的成像模拟结果表明：40 MeV高能电子暗场成像技术在铝样品厚度小于25 μm情况下具有明显的面密度分辨优势，且空间分辨率达到μm量级，非常适用于高能量密度物质诊断。Abstract: The simulations of dark-field imaging of high energy electron radiography show that the dark field imaging is distorted in the case of large angle selected. In order to eliminate distortion, an optimized scheme is proposed in this paper. The results of high Energy Electron Radiography (HEER) simulations by optimization show that the dark-field image has better areal density resolution when the thickness of aluminum target is less than 25 μm, and the spatial resolution of dark-field imaging is about several microns. In summary, dark-field imaging of high energy electron radiography is ideal to thin warm dense matter specimen diagnosis.
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图 1 高能电子成像原理示意图(在线彩图)
Figure 1. The schematic of high energy electron radiography (color on line)
图 2 暗场成像原理示意图。将光阑位置设定为绿色区域，则为明场成像; 设定为红色区域，则为暗场成像
Figure 2. Schematic of dark-field image. When the aperture position is set in the green area, the image is bright-field; when the aperture is set to the red area, the dark field image can be got
图 5 40 MeV电子束透射不同厚度铝样品，电子数密度在Fourier面处沿x轴分布图
Figure 5. Distribution of electrons along x-axis at Fourier plane in the case of the 40 MeV electron beam passing through the aluminum specimen with different thickness
图 6 不同光阑中心位置对应的像平面上电子数密度分布图
Figure 6. Results of HEER for different aperture position setting
图 7 劈裂尺寸模拟值与理论值对比图
Figure 7. Comparison of theoretical and simulated values of the crack size
图 11 不同狭缝位置与对应入射角度情况下电子数分布拟合曲线对比图
Figure 11. Fitting curve of electron number distribution at image plane for different aperture position and different incident angles setting
图 12 不同入射角度情况下，厚度分辨本领随厚度变化关系图
Figure 12. Capabilities of areal density resolution under different incident angle
表 1 靶平面至Fourier面处的传输矩阵参数
Table 1. Matrix parameters of transport from object plane to Fourier plane
R11F R12F/(mm·mrad-1) R33F R34F/(mm·mrad-1) -3.0×10-3 1.1 -6.7×10-3 -5.3 
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表 2 成像系统传输矩阵参数
Table 2. Matrix parameters of transport from object plane to image plane
R11 R12/(mm·mrad-1) R21/(mm·mrad-1) R22 R33 R34/(mm·mrad-1) R43/(mm·mrad-1) R44 -1.0 -6.67×10-3 4.8×10-3 -1.0 -1.0 -7.10×10-3 2.35×10-2 -1.0
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表 3 不同光阑位置对应的角度筛选区间
Table 3. Angle range selected for different aperture position setting
xaperture/mm angle selected/mrad xaperture/mm angle selected/mrad 0 －0.23~0.23 10 8.86~9.32 5 4.32~4.78 15 13.40~13.87
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表 4 不同入射角度情况下，对于不同厚度铝样品的空间分辨
Table 4. Spatial resolution for different steps and different incident angle
incident angle/mrad RMS spatial resolution for different steps/μm 7 μm 14 μm 28 μm 56 μm 112 μm 224 μm 0 5 6 5 4 2 3 4.54 3 2 10 9 14 5 9.09 3 1 7 5 2 3 13.64 1 5 2 10 3
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[1] Council N, Ebrary I. Frontiers in high energy density physics: the X-games of contemporary science[M]. National Academies Press, 2003. [2] Zhao Yongtao, Zhang Zimin, Gai Wei, et al. High energy electron radiography scheme with high spatial and temporal resolution in three dimension based on a e-LINAC[J]. Laser and Particle Beams, 2016, 34(2): 338-342. doi: 10.1017/S0263034616000124 [3] Merrill F, Harmon F, Hunt A, et al. Electron radiography[J]. Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2007, 261(1/2): 382-386. [4] Merrill F E, Goett J, Gibbs J W, et al. Demonstration of transmission high energy electron microscopy[J]. Applied Physics Letters, 2018, 112: 144103. doi: 10.1063/1.5011198 [5] Zhao Quantang, Cao Shuchun, Shen Xiaokang, et al. Design and simulation study of ultra-fast beam bunches split for three orthogonal planes high-energy electron dynamic radiography[J]. Laser and Particle Beams, 2017, 35(4): 579-586. doi: 10.1017/S0263034617000647 [6] Zhao Quantang, Cao Shuchun, Liu Ming, et al. Beam optical design for high energy electron radiography experiment study based on THU LINAC[J]. Physics, 2015. [7] Zhou Zheng, Du Yingchao, Cao Shuchun, et al. Experiments on bright-field and dark-field high-energy electron imaging with thick target material[J]. Physical Review Accelerators and Beams, 2018, 21: 074701. doi: 10.1103/PhysRevAccelBeams.21.074701 [8] 卢亚鑫, 杨国君, 魏涛, 等. 高能电子照相成像模糊模拟研究[J]. 强激光与粒子束, 2016, 28: 014002. doi: 10.11884/HPLPB201628.014002Lu Yaxin, Yang Guojun, Wei Tao, et al. Image blur in high energy electron radiography. High Power Laser and Particle Beams, 2016, 28: 014002 doi: 10.11884/HPLPB201628.014002 [9] Wei Tao, Li Yiding, Yang Guojun, et al. An accelerator scenario for a hard X-ray free electron laser combined with high energy electron radiography[J]. Chinese Physics C, 2016, 40: 088101. doi: 10.1088/1674-1137/40/8/088101 [10] 王致远, 杜应超, 黄文会. 基于蒙卡和粒子示踪程序的电子成像模拟分析[J]. 强激光与粒子束, 2014, 26: 114007. doi: 10.11884/HPLPB201426.114007Wang Zhiyuan, Du Yingchao, Huang Wenhui. Simulation analysis of electron imaging method based on Monte Carlo simulation and particle tracer software. High Power Laser and Particle Beams, 2014, 26: 114007 doi: 10.11884/HPLPB201426.114007 [11] Xiao Jiahao, Zhang Zimin, Cao Shuchun, et al. Areal density and spatial resolution of high energy electron radiography[J]. Chinese Physics B, 2018, 27: 035202. doi: 10.1088/1674-1056/27/3/035202 [12] Jiang Xiaoguo, Wang Yuan, Yang Zhiyong, et al. Time-resolved measurement technique for pulsed electron beam envelope basing on framing and streaking principle[J]. Chinese Physics C, 2016, 40: 017003. doi: 10.1088/1674-1137/40/1/017003 [13] 江孝国, 王远, 代志勇, 等. 高速分幅相机在强流脉冲电子束调试中的应用研究[J]. 激光与光电子学进展, 2014, 51: 022201. https://www.cnki.com.cn/Article/CJFDTOTAL-JGDJ201402022.htmJiang Xiaoguo, Wang Yuan, Dai Zhiyong, et al. Application of high speed framing camera in debugging of high current and pulsed electron beam. Laser & Optoelectronics Progress, 2014, 51: 022201 https://www.cnki.com.cn/Article/CJFDTOTAL-JGDJ201402022.htm [14] Alber I, Bagnoud V, Brown C R D. Proton acceleration experiments and warm dense matter research using high power lasers[J]. Plasma Physics & Controlled Fusion, 2009, 51(12): 559-566. [15] Ernstorfer R, Harb M, Hebeisen C T, et al. The formation of warm dense matter: experimental evidence for electronic bond hardening in gold[J]. Science, 2009, 323(5917): 1033-1037. doi: 10.1126/science.1162697 [16] Koenig M, Benuzzi-Mounaix A, Ravasio A, et al. Progress in the study of warm dense matter[J]. Plasma Physics and Controlled Fusion, 2005, 47(12B): B441. [17] Odeblad E. Further approximate studies on beta ray absorption and transmission[J]. Acta Radiologica, 1957(4): 289-306. [18] Brown K L. A first and second-order matrix theory for the design of beam transport systems and charged particle spectrometers[J]. Advances in Particle Physics, 1968(1): 71-134. [19] Lynch G R, Dahl O I. Approximations to multiple Coulomb scattering[J]. Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 1991, 58(1): 6-10. doi: 10.1016/0168-583X(91)95671-Y [20] Hirayama H, Namito Y, Nelson W R, et al. The EGS5 code system[R]. SLAC-R-730. 2007. [21] PARMELA. http://laacg.lanl.gov/laacg/services/serv_codes.phtml. 期刊类型引用(1)
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