Restore Nuclear Radiation Field Of Unknown Radioactive Sources And Research On Intelligent Random Search And Optimization

In the process of nuclear energy exploited and applied, nuclear safety is the first problem to be considered. In the high-level radioactive environment, how to reduce the radiation field and quickly search and clear the nuclear radioactive sources is a great significance to develop the strategy of nuclear emergency response. More ways to solve the search problems are the use of detection apparatus for searching. Under special circumstances, the search efficiency is very low and the personal safety are the bottleneck problem that restricts the technology of search nuclear source.With the rapid development of nuclear industry and the widespread application of nuclear technology, research on security of radioactive sources,especially, the intelligent search of the unknown radioactive sources, which is even more important.The physical characteristics of nuclear radiation field was first discussed. It was taken into account that the value of radioactive concentration at any point is inversely proportional to the square of the distance from nuclear sources. The nuclear radiation field is restored with mathematical structural method, which has the characteristics of nuclear source. At same time, using the radiation field data restored, heuristic intelligent search algorithm was designed. This article implemented intelligent search based on human-computer interaction.The paper is mainly described from the four aspects.(1) A new method is proposed to study the inverse reduction of nuclear radiation field by mathematical structural method.Taking fully into account the characteristics of the radioactive source, the radioactive concentration value is inversely proportional to the square of the distance from the nuclear sources. Based on the slope of the continuous change, the radiation concentration value was restored and concentration curve of one dimensional is obtained and two-dimensional radiation concentration field function is constructed by the concentration dominant of the adjacent points. Therefore, the surface of concave function with the characteristic of radiation source was obtained. At the same time, the approximate concentration value of any point in the radiation field was also got. Experimental results showed the error is 3.19% between the radiation measurement function to be formed and the real radiation measurement field. The constructed function was more close to the real radiation field.Created a new method restored the nuclear radiation field by math structural method.(2) In the area of radioactive sources existing, the search area of the radioactive source was defined. In accordance with the search problem for point source, the theory of threshold algorithm was designed under different circumstance. A mathematical algorithm to identify the radioactive source is designed, according to the concave function of the radioactive source.(3) In order to quickly search the unknown source in a short time, a heuristic algorithm is selected and the line scan search algorithm is designed. Due to the radioactive source only appear in the data of maximum points, the heuristic algorithm of the two fitting line and the three fitting line scan search algorithm are designed, whcih improve the search efficiency and precision and the search method is optimized. The experimental results show that the search algorithm can preferably locate the source of radioactive source in a reasonable time.(4) A probability optimization model of stochastic search is proposed, which imitate typical search experience and was realized by computer. A combination of the random search with heuristic search, it makes random search algorithm to adapt to the actual search in a variety of complex situations. The algorithm has the function of automatic recognition and correction of data misreading, fast searching of large step size and jumping out of the low concentration area. Especially for the multiple sources, designed single and multi-chain intelligent random search algorithm. If there are obstacles in the area, the algorithm was designed to automatically recognize the obstacles and track the maximum direction, which has the strong adaptability. At last, the computer simulation is used to simulate the above complex conditions, random search algorithms were testified in the experiment, which can accurately locate the radioactive sources. Random search algorithm can save data acquisition and reduce exposure risk. Under human-computer interaction mode, the computeraided intelligent search was realized, which create a new way to search the radioactive source.