Construction And Power Spectrum Analysis Of System Of Random Nuclear Signal Generated By Nuclear Materials Driven By Imitated Californium Source

Since the1945, the moment of U.S. nuclear missiles fell on Hiroshima andNagasaki, nuclear weapons, because of its enormous power, as well as catastrophicdestructive, are serious threat to global security and human survival and has become ahanging in the human heada “sword of Damocles”. How to effectively prevent andcontrol the spread of nuclear weapons has been a serious issue of concern for theinternational community. Because of the key of verification of nuclear arms control isthe verification of nuclear materials, mastering effective verification technology isdirectly related to the fight for equal rights in the verification of arms control anddisarmament treaties, but also related to the country’s sovereignty and security interests.Nuclear material is the core of nuclear weapons, and therefore, the key of verificationtechnology lies in how to effectively rapid and accurate identification of nuclearmaterial properties, and the basis of the study is the nuclear signal what can vividlyreflect the process of nuclear reaction.For these reasons, this paper, based on the nuclear arms control verification theory,relying on the science and technology projects of the Defense Major Projects （ProjectNo.: GFZX02040307） and the National Natural Science Foundation （Project No.:61175005）, take the lead to carry out the system construction and the simulation andresearch work in the country which is based on²⁵²Cf neutron source driven system ofnuclear material. A lot of disadvantages to identify the nuclear materials due to itssensitivity, dangers of strong radioactive radiation and other factors makes the study ofnuclear material difficult. This paper, starting from the physical principles and teststatistics, constructs nuclear materials identification system simulation model, obtainsthe sampling process of particle transport with the Monte Carlo method, acquires thethree channels of time domain pulse signal. And by means of Time-Frequency DomainAnalysis, Auto-Correlation Functions （AC）, Cross-Correlation Functions （CC）, AutoPower Spectral Densities （APSD） and Cross Power Spectral Densities （CPSD） betweendifferent channels can obtain several signatures, which can show some characters ofnuclear material （Time-Frequency Dependent Signatures）. The simulation results showthat the simulation model constructed in this article, process simulation and datacalculation can perfectly reflect the particle transport process of nuclear fission, and canpresent the effectiveness of several signatures of the nuclear materials identification system, and laid the foundation to carry out the related experment and interpretation andanalysis of the characteristic lines in follow-up and actual conditions, also is of positivesignificance for laboratory simulation study of nuclear arms control verificationtechnology.The simulation studies and Time-Frequency analysis laid the foundation of studyof the random nuclear signal recognition with nuclear materials, and can help to furtherunderstand the nature of the active measurement （Source-Driven Noise AnalysisMethod）, and is of importance and far-reaching significance for the promotion ofpracticality and functionality of verification system.