Reconstructing mass and enrichment of uranium shell based on associated particle imaging

Abstract

In the field of arms control verification, the attributes of uranium shells often need to be measured and authenticated. In this paper, the feasibility and results of reconstructing the masses and enrichment of uranium shells based on the associated particle imaging are studied, aiming at constructing and testifying the theoretical framework of this method. First, the basic principles of this method are introduced. Second, the physical model of the neutron transmission imaging of uranium shells was constructed, and the feasibility of reconstructing the masses of uranium shells based on the neutron transmission imaging was proved with the uncertainties of the reconstruction results analyzed. Third, the physical model of the neutron induced fission imaging of uranium shells was constructed, and reconstructing the enrichment of uranium shells based on the neutron transmission imaging and neutron induced fission imaging was proved to be feasible, and the influencing factors of the uncertainties of the reconstruction results were analyzed. Meanwhile, a method of reconstructing the enrichment of uranium shells based on a single calibration line and a method of revising neutron attenuation and multiplication effect are proposed; based on the above two methods, the reconstruction uncertainties of the enrichment of uranium shells can reach the level of 3.78%.