Effect of radioactive material 137Cs on microwave breakdown characteristics
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摘要: 针对现有的放射性物质探测手段有效距离近和效率较低等局限性，考虑到高功率微波（HPM）良好的空间辐射特性，研究放射性物质对微波大气击穿特性的影响，以实现利用HPM远距离探测放射性物质的设想。阐释了微波脉冲等离子体击穿原理和自由电子对击穿特性影响，分析了放射性物质137Cs射线产生自由电子的过程，在此基础上分析了HPM大气击穿时间和击穿阈值。基于HPM大气击穿等离子体实验装置，分别在6000 Pa、7000 Pa和8000 Pa的低气压环境对有、无放射源存在情形开展多次HPM辐照实验。实验结果表明：放射源的存在降低了约10%的HPM大气击穿阈值，缩短约50%的击穿时间。Abstract: In view of the limitations such as close effective distance and low efficiency of the existing radioactive source detection methods, high-power microwave (HPM) is used to detect radioactive materials over a long distance because of its good spatial radiation characteristics. In this paper, the principle of microwave pulsed plasma breakdown and the influence of free electrons on breakdown characteristics are explained, the process of free electrons generated by the decay of radioactive source 137Cs is analyzed, and the HPM breakdown time and breakdown threshold are presented. Based on the HPM atmospheric breakdown plasma experimental apparatus, HPM irradiation experiments were performed multiple times in the low-pressure environment of 6000 Pa, 7000 Pa and 8000 Pa with presence and absence of radioactive sources. Experimental results show that the presence of a radioactive source lowers the HPM breakdown threshold by approximately 10% and can reduce the breakdown time by approximately 50%.
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图 3 60 s内击穿概率随场强变化对比
Figure 3. Comparison of breakdown probabilities varying with field strength within 60s
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[1] 王百荣, 田新, 杨忠平. 非法运输放射性物质的探查[J]. 辐射防护, 2005, 25(6):376-379 doi: 10.3321/j.issn:1000-8187.2005.06.008Wang Bairong, Tian Xin, Yang Zhongping. Detection of illicit trafficking of radioactive materials[J]. Radiation Protection, 2005, 25(6): 376-379 doi: 10.3321/j.issn:1000-8187.2005.06.008 [2] 杨敏, 党瑞荣, 刘彤, 等. 放射性探测器发展分析以及应用介绍[J]. 石油仪器, 2009, 23(5):44-45Yang Min, Dang Ruirong, Liu Tong, et al. Development analysis and application of radioactivity detectors[J]. Petroleum Instruments, 2009, 23(5): 44-45 [3] 张玉敏. 国外放射性探测装备和技术的发展现状与趋势[J]. 舰船防化, 2009(1):1-5Zhang Yumin. Development of overseas radioactive detecting technology[J]. Chemical Defence on Ships, 2009(1): 1-5 [4] 李惠彬, 冯元举, 韩斌. 航空放射性测量技术对核事故泄露核素的探测能力评估[C]//第十六届全国核电子学与核探测技术学术年会论文集(下册). 绵阳: 中国电子学会核电子学与核探测技术分会, 2012: 429-433Li Huibin, Feng Yuanju, Han Bin. Evaluation of the detection capability of aeronautical radiometric technology on nuclear accident leaked nuclides[C]//The 16th National Annual Conference on Nuclear Electronics and Nuclear Detection Technology. Mianyang: Branch of Nuclear Electronics and Nuclear Detection Technology, China Electronics Society, 2012: 429-433 [5] Sprangle P, Hafizi B, Milchberg H, et al. Active remote detection of radioactivity based on electromagnetic signatures[J]. Physics of Plasmas, 2014, 21: 013103. doi: 10.1063/1.4861633 [6] Nusinovich G S. Remote detection of concealed radioactive materials by using focused powerful terahertz radiation[J]. Journal of Infrared, Millimeter, and Terahertz Waves, 2016, 37(6): 515-535. doi: 10.1007/s10762-016-0243-3 [7] Kim D, Yu D, Sawant A, et al. Remote detection of radioactive material using high-power pulsed electromagnetic radiation[J]. Nature Communications, 2017, 8: 15394. doi: 10.1038/ncomms15394 [8] 周前红, 孙会芳, 董志伟, 等. 微波大气击穿阈值的理论研究[J]. 物理学报, 2015, 64:175202 doi: 10.7498/aps.64.175202Zhou Qianhong, Sun Huifang, Dong Zhiwei, et al. Theoretical study on the microwave air breakdown threshold[J]. Acta Physica Sinica, 2015, 64: 175202 doi: 10.7498/aps.64.175202 [9] 闫二艳, 邱风, 孟凡宝, 等. HPM大气击穿特性初步研究[C]//第十届全国高功率微波学术研讨会论文集. 2015: 319-322Yan Eryan, Qiu Feng, Meng Fanbao, et al. Preliminary study on atmospheric breakdown characteristics of HPM[C]//Proceedings of the 10th National Symposium on HPM. 2015: 319-322 [10] 曹金坤, 周东方, 牛忠霞, 等. 重复频率高功率微波脉冲的大气击穿[J]. 强激光与粒子束, 2006, 18(1):115-118Cao Jinkun, Zhou Dongfang, Niu Zhongxia, et al. Air breakdown by repetition-rate high power microwave pulse[J]. High Power Laser and Particle Beams, 2006, 18(1): 115-118 [11] 朱连燕. 重复频率高功率微波脉冲大气击穿的理论研究[D]. 成都: 西南交通大学, 2014: 5-14Zhu Lianyan. The orical studies of air breakdown by repetition-rate high power microwave pulse[D]. Chengdu: Southwest Jiaotong University, 2014: 5-14 [12] 蔡北兵, 余道杰, 周东方, 等. 氧负离子解吸附过程HPM大气击穿弛豫时间分析[J]. 强激光与粒子束, 2017, 29:113004 doi: 10.11884/HPLPB201729.170265Cai Beibing, Yu Daojie, Zhou Dongfang, et al. Analysis of air breakdown relaxation time of high power microwave based on o− detachment[J]. High Power Laser and Particle Beam, 2017, 29: 113004 doi: 10.11884/HPLPB201729.170265 [13] 赵刚, 闫二艳, 陈朝阳, 等. 高功率微波大气击穿阈值分析及实验[J]. 强激光与粒子束, 2013, 25(s1):111-114Zhao Gang, Yan Eryan, Chen Chaoyang, et al. Analysis and experimental study on threshold of air breakdown by high power microwave[J]. High Power Laser and Particle Beams, 2013, 25(s1): 111-114 [14] 胡涛, 周东方, 李庆荣, 等. 电子弛豫过程对重复频率高功率微波大气击穿的影响[J]. 强激光与粒子束, 2009, 21(4):545-549Hu Tao, Zhou Dongfang, Li Qingrong, et al. The effect of electronic relaxation process on air breakdown caused by repetition frequency HPM[J]. High Power Laser and Particle Beams, 2009, 21(4): 545-549 [15] Yu Daojie, Chai Mengjuan, Zhou Dongfang, et al. Research on dielectric focusing lens antenna for HPM atmospheric breakdown experiments[J]. Chinese Journal of Electronics, 2019, 28(1): 202-206. doi: 10.1049/cje.2018.09.004 [16] Dimant Y S, Nusinovich G S, Sprangle P, et al. Propagation of gamma rays and production of free electrons in air[J]. Journal of Applied Physics, 2012, 112: 083303. doi: 10.1063/1.4762007 [17] 欧阳建明. 高空核爆炸背景下大气的电离过程及其影响研究[D]. 长沙: 国防科学技术大学, 2014: 37-41Ouyang Jianming. The research on ionization processes and ionization effects of atmosphere by high-altitude nuclear explosions[D]. Changsha: National University of Defense Technology, 2014: 37-41 -
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