Meng Huang, Jianyu Zhu, Jun Wu, Rui Li
Institute of Applied Physics and Computational Mathematics, Beijing 100094, China.
Center for Strategic Studies, China Academy of Engineering Physics, Beijing 100088, China.
Appl Radiat Isot. 2019 Jan;143:11-17. doi: 10.1016/j.apradiso.2018.10.010. Epub 2018 Oct 12.
The future international nuclear disarmament may involve the dismantlement of nuclear warheads. After the dismantlement of a nuclear warhead, the separated explosive needs authentication that it comes from the dismantled nuclear warhead. In this paper, the Monte Carlo numerical simulation method was used to study the feasibility and result of determining the source of the explosive by analyzing the nuclide abundances of the explosive and determining the age of the explosive (calculated since the explosive was placed in the nuclear warhead). First, the JMCT software was used to analyze the nuclei produced by the neutron reactions in the explosive of the nuclear warhead. As a result, it was found that C is the most promising to be used to determine the source of the explosive. Second, the relationships between the average abundance of C and the age of the explosive, the spatial distribution of the C abundance in the explosive were calculated by using the JMCT software. Finally, it is found that, compared to the WgPu warheads (nuclear warheads with weapons-grade plutonium cores), the C abundances of the explosives of the WgU warheads (nuclear warheads with weapons-grade uranium cores) are much lower (the ages of the explosives are the same), and it is more difficult to measure the latter; for the WgPu warheads with the structures based on Model 3 and Model 4 (the warhead models employed were proposed by Steve Fetter), it can be determined that whether the separated explosives come from the dismantled nuclear warheads or are common ones (or the fake ones prepared by the verified party) after the dismantlement of the nuclear warheads by measuring the C abundances in the explosives (including the average abundances and the spatial distributions of the abundances) and determining the ages of the explosives, which realizes the source authentication of the explosives.
未来的国际核裁军可能涉及核弹头的拆解。核弹头拆解后，分离出的炸药需要鉴定其是否来自被拆解的核弹头。本文采用蒙特卡罗数值模拟方法，通过分析炸药的核素丰度并确定炸药的年龄（自炸药置于核弹头中起计算）来研究确定炸药来源的可行性及结果。首先，利用JMCT软件分析核弹头炸药中中子反应产生的原子核。结果发现，碳最有希望用于确定炸药的来源。其次，利用JMCT软件计算了碳的平均丰度与炸药年龄之间的关系以及炸药中碳丰度的空间分布。最后发现，与WgPu弹头（以武器级钚为芯的核弹头）相比，WgU弹头（以武器级铀为芯的核弹头）炸药中的碳丰度要低得多（炸药年龄相同），且对后者的测量更困难；对于基于模型3和模型4的WgPu弹头（采用的弹头模型由史蒂夫·费特提出），在核弹头拆解后，通过测量炸药中的碳丰度（包括丰度的平均值和空间分布）并确定炸药的年龄，能够确定分离出的炸药是否来自被拆解的核弹头，还是普通炸药（或核查方制备的假炸药），从而实现了炸药的来源鉴定。
