Investigation on detecting the symmetric attribute of plutonium component

It can promote the mutual confidence of the parties related to nuclear arms control if some technical means can be used to verify that a declared sealed canister does contain the declared plutonium component. Since symmetry is one of the important attributes of the plutonium component, detecting the symmetric attribute of plutonium component becomes reasonable in order to confirm the authentication of the plutonium component. This paper reports our investigation on detecting the axis symmetry of three plutonium samples using a high-resolution γ spectrometer and a rotative canister holder. The investigation shows that the rotative γ-ray monitoring is a sensitive way to detect the axis symmetry of plutonium material, and that in order to make a correct detection two pre-conditions must be meet: 1) the canister must be cylindrical; 2) the contained plutonium material must be placed with its symmetric axis (assuming it has) along with the canister cylindrical axis. (authors)