To solve the difficulties in complex gray-scale source definition and simulation efficiency
a strategy for defining complex gray-scale source based on the depth-first merger is proposed. A technology of cells merging is used to reduce the number of cells for the source definition and ensure the sampling efficiency of source in Monte Carlo simulation
thus the simulation efficiency of coded imaging of the complex gray-scale source can be increased. When the simulated source is the binary letter E source
the error of simulated coded image of the merged source remains same as that of the source without merging and meets the requirement of the reconstruction for statistics
while the computing time for merged source is reduced to 1/5 of the source without merging. The 16
64 and 256 gray-scale letter E sources are defined by the definition method of complex gray-scale source based on the depth-first merger
and the corresponding simulations of coded image are also carried out. The errors of simulation results reach less than 1%
which meet the requirement of the reconstruction for statistics. The complex binary source of Xi'an Jiaotong University school badge is defined with the proposed strategy for complex gray-scale source based on the depth-first merger and the corresponding simulation of coded image is carried out
then the reconstructions of the source by three different methods are realized. The strategy for defining complex gray-scale source based on the depth-first merger is verified
so it can be expected to provide a feasible technological approach to enhance the adaptability of diagnosis of the complex capsule implosion process.
关键词
Keywords
references
PFALZNER S. 惯性约束聚变导论 [M]. 崔旭东, 译. 北京: 原子能出版社, 2011: 1-20.
VOLEGOV P L, DANLY C R, FITTINGHOFF D N, et al. Self characterization of a coded aperture array for neutron source imaging [J]. Rev Sci Instrum, 2014, 85(12): 123506.
VOLEGOV P, DANLY C R, FITTINGHOFF D N, et al. Neutron source reconstruction from pinhole imaging at National Ignition Facility [J]. Rev Sci Instrum, 2014, 85(2): 023508.
WILSON D C, ARAGONEZ R J, ARCHULETA T N, et al. Comparing neutron and X-ray images from NIF implosions [J]. EPJ Web of Conferences, 2013, 59: 04002.
GRIM G P, ARCHULETA T N, ARAGONEZ R J, et al. Summary of the first neutron image data collected at the National Ignition Facility [J]. EPJ Web of Conferences, 2013, 59: 13017.
HURRICANE O A, CALLAHAN D A, CASEY D T, et al. Fuel gain exceeding unity in an inertially confined fusion implosion [J]. Nature, 2014, 506(7488): 343-348.
张天奎. 快中子编码成像技术中的图像重建方法研究 [D]. 西安: 西安交通大学, 2013.
BRIESMEISTER J F. MCNP: a general Monte Carlo N-particle transport code, Version 4C [R]. Los Alamos, USA: Los Alamos National Laboratory, 2000.
SHULTIS J K, FAW R E. An MCNP primer [M]. Manhattan, USA: Kansas State University, 2006: 16-20.
BARRERA C. Experimental component characterization, Monte Carlo-based image generation and source reconstruction for the Neutron Imaging System of the National Ignition Facility [D]. Berkeley, USA: University of California at Berkeley, 2007.
X-5 Monte Carlo Team. MCNP: a general Monte Carlo N-particle transport code, version 5 [R]. Los Alamos, USA: Los Alamos National Laboratory, 2003.
RICHARDSON W H. Bayesian-based iterative method of image restoration [J]. Journal of the Optical Society of America, 1972, 62(1): 55-59.
LUCY L B. Iterative technique for rectification of observed distributions [J]. The Astronomical Journal, 1974, 79(6): 745-754.
ZHAO Z G, DING Y K, DONG J J, et al. Richardson-Lucy method for decoding X-ray ring code image [J]. Plasma Physics and Controlled Fusion, 2007, 49(8): 1145-1150.
RESS D, LERCHE R A, ELLIS R J, et al. Neutron imaging of laser fusion-targets [J]. Science, 1988, 241(4868): 956-958.
RESS D, LERCHE R A, ELLIS R J, et al. Neutron imaging of inertial confinement fusion-targets at Nova [J]. Review of Scientific Instruments, 1988, 59(8): 1694-1696.
ZHANG T K, HU H S, JIA Q G, et al. Genetic algorithms applied to reconstructing coded imaging of neutrons and analysis of residual watermark [J]. Rev Sci Instrum, 2012, 83(11): 113505.