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传统的X射线无损检测应用广泛, 但X射线对低原子序素构成为主的爆炸物不能进行有效的甄别; 中子穿透能力较强, 能和原子核相互作用产生特征γ射线, 因此中子无损检测方法能有效弥补X射线无损检测方法的不足。 介绍了几种常用的中子无损检测方法, 并采用脉冲快热中子法(为PFTNA)的方法对模拟爆炸物进行了测量。 实验结果表明, 利用密封中子发生器和采用PFTNA方法进行爆炸物检测是可行的。 Traditional X ray scatheless detecting method is used widely, but it is not useful to discriminate explosive consisting of low Z atomic elements. The penetrability of neutron is much better, and it can interact on atomic nucleus to emit characteristic γ ray. So neutron scatheless detecting methods can the used to detect the low Z atomic elements. In this paper, several neutron scatheless detecting methods are introduced briefly, and the principium experiment using Pulse Fast Thermal Neutron Analysis(PETNA) to detect a kind of explosive simulacrum is carried out. The experiment results show that PFTNA based on the sealed neutron generator is feasible to detect explosive. 相似文献
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中子检测隐藏爆炸物技术的研究进展 总被引:2,自引:0,他引:2
对中子检测隐藏爆炸物技术的基本原理作了较详细的介绍,对几种不同的检测方法进行了比较,分析了当前国内外的研究现状,并指出了未来的发展方向。In this paper, several methods and basic principles of neutron detecting latent explosive are introduced and analyzed in details. The progresses in this field are reviewed and further development direction is also prospected. 相似文献
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近年来国际上恐怖活动猖獗,民航飞机因放入爆炸物而造成机毁人亡的恶性事件时有发生,对民航安全造成极大威胁.特别是新型塑料爆炸物的检测,成为人们研究的重要课题.塑性爆炸物具有氮、氧等轻元素含量较高、不导电、无磁性、密度低、蒸汽压低等特点.它的爆炸威力大,约0.5公斤这类炸药就足以使一架大型客机爆炸坠落.要在大量行李中检测出如此少量的爆炸物,是件困难的事情. 相似文献
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近年来,恐怖袭击、刑事犯罪等爆炸事件频发,对社会的公共安全构成了严峻挑战。炸药是各种爆炸物的核心成分,因此对炸药的分析检测与识别是公共安全领域研究的热点之一。表面增强拉曼光谱可以对爆炸物分子实现指纹谱性、超痕量、实时高效的探测和识别,在安全检测和法庭科学等公共安全领域展现了极具诱惑力的应用前景。最近几年,国际上针对表面增强拉曼光谱检测爆炸物的研究十分活跃,取得了丰富的成果,文章综述了爆炸物表面增强拉曼基底,包括表面修饰改性和复合功能结构基底;有机和无机爆炸物的检测;以及爆炸物光谱识别的研究进展。分析了需要面对的问题,并总结展望了未来的发展趋势。相信随着纳米科学与技术、表面科学、仪器科学以及深度学习等新兴科技的快速发展,表面增强拉曼光谱一定能在爆炸物检测和识别方面取得更大进展。 相似文献
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源中子脉冲的脉宽和滞空是脉冲快热中子分析技术的两个关键时序参数,但目前国内外还没有针对上述参数的量化评估及设置方法的相关文献报道。针对这一现状,定义了时序优化的量化评估函数,进而建立了一种时序参数优化的理论解析模型,并通过将待测目标物与周边介质等效为线性时不变系统,简化了计算过程。从数学上证明了基于该模型获取的中子脉冲的最优脉宽和滞空应相等。以美国研制的脉冲中子元素分析仪应用于地雷探测时的场景为例,获取了该场景下的最优时序参数,并论证了该模型对环境介质、探测布局的适应性。结果表明,该理论模型能快速有效地获取特定应用场景下的最优时序参数,且对探测背景、探测布局均具有较强的适应性。提出的理论模型可为脉冲快热中子分析技术应用于物料分析、违禁品探测、地雷探测等领域提供参考。 相似文献
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A new thermal neutron detector with a domestically produced THGEM (Thick Gas Electron Multiplier) was developed as an alternative to 3He to meet the needs of the next generation of neutron facilities. One type of Au-coated THGEM was designed specifically for neutron detection. A detector prototype has been developed and the preliminary experimental tests are presented, including the performance of the Au-coated THGEM working in Ar/CO2 gas mixtures and the neutron imaging test with 252Cf source, which can provide the reference for experimental data for research in the future. 相似文献
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为多种复杂环境下的稳态和脉冲DT聚变中子能谱测量建立了一种灵敏度优化反冲质子磁谱仪. 使用成像板和同位素α源测量了谱仪的反冲质子能量-位置投影关系. 利用稳态加速器中子源平台、通过单粒子计数方法结合三维带电粒子输运程序模拟,研究了谱仪脉冲中子灵敏度能量响应. 通过高探测效率参数设置使谱仪对DT中子的探测效率达到2×10-5 cm2水平,从而在较弱中子源上获得了较高统计精度实验数据. 程序模拟结果与谱仪α粒子刻度和DT中子标定实验结果取得了良好的一致性,可由此发展精细解谱技术,以提高脉冲中子能谱测量的灵敏度和能量分辨.
关键词:
聚变中子能谱
磁反冲质子
脉冲中子灵敏度
粒子输运 相似文献
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Influence of thermal and resonance neutron on fast neutron flux measurement by 239Pu fission chamber
The 239Pu fission chambers are widely used to measure fission spectrum neutron flux due to a flat response to fast neutrons. However, in the meantime the resonance and thermal neutrons can cause a significant influence on the measurement if they are moderated, which could be eliminated by using 10B and Cd covers. At a column enriched uranium fast neutron critical assembly, the fission reaction rates of 239Pu are measured as 1.791× 10-16, 2.350×10-16 and 1.385× 10-15 per second for 15 mm thick 10B cover, 0.5 mm thick Cd cover, and no cover respectively, while the fission reaction rate of 239Pu is rapidly increased to 2.569× 10-14 for a 20 mm thick polythene covering fission chamber. The average 239Pu fission cross-section of thermal and resonance neutrons is calculated to be 500 b and 24.95 b with the assumption of 1/v and 1/E spectra respectively, then thermal, resonance and fast neutron flux are achieved to be 2.30× 106, 2.24× 106 and 1.04× 108 cm-2·-1. 相似文献
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V. M. Bystritsky N. I. Zamyatin E. V. Zubarev V. L. Rapatsky Yu. N. Rogov I. V. Romanov A. B. Sadovsky A. V. Salamatin M. G. Sapozhnikov M. V. Safonov V. M. Slepnev A. V. Philipov 《Physics of Particles and Nuclei Letters》2013,10(5):442-446
The results of using a stationary setup for detecting and identifying explosives using the tagged neutron method (or associated particle imaging (API) method) have been presented. The source of 14.1-MeV tagged neutron beams is an ING-27 portable neutron generator made by VNIIA (Moscow). It contains an embedded 64-pixel silicon α detector with double-sided strip readout developed by the Joint Institute for Nuclear Research (JINR). The setup was tested for the identification of more than 30 explosives. 相似文献
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Fazal-ur-Rehman M.I. Al-Jarallah F. Abu-Jarad M.A. Qureshi 《Radiation measurements》2005,40(2-6):595-600
A set of five 241Am–Be neutron sources are utilized in research and teaching at King Fahd University of Petroleum and Minerals (KFUPM). Three of these sources have an activity of 16 Ci each and the other two are of 5 Ci each. A well-shielded storage area was designed for these sources. The aim of the study is to check the effectiveness of shielding of the KFUPM neutron source storage area. Poly allyl diglycol carbonate (PADC) Nuclear track detectors (NTDs) based fast and thermal neutron area passive dosimeters have been utilized side by side for 33 days to assess accumulated low ambient dose equivalents of fast and thermal neutrons at 30 different locations around the source storage area and adjacent rooms. Fast neutron measurements have been carried out using bare NTDs, which register fast neutrons through recoils of protons, in the detector material. NTDs were mounted with lithium tetra borate (Li2B4O7) converters on their surfaces for thermal neutron detection via and nuclear reactions. The calibration factors of NTD both for fast and thermal neutron area passive dosimeters were determined using thermoluminescent dosimeters (TLD) with and without a polyethylene moderator. The calibration factors for fast and thermal neutron area passive dosimeters were found to be 1.33 proton tracks and 31.5 alpha tracks , respectively. The results show variations of accumulated dose with the locations around the storage area. The fast neutron dose equivalents rates varied from as low as up to whereas those for thermal neutron ranged from as low as up to . The study indicates that the area passive neutron dosimeter was able to detect dose rates as low as 7 and from accumulated dose for thermal and fast neutrons, respectively, which were not possible to detect with the available active neutron dosimeters. 相似文献
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In this paper, the results of computational simulation of experiments with the MK-I core of the JOYO fast neutron sodium-cooled reactor are presented. The MCU-KS code based on the Monte Carlo method was used for calculations. The research was aimed at additional verification of the MCU-KS code for systems with a fast neutron spectrum. 相似文献