High thermo-separation efficiency of Tc from molten MoO samples by repeated milking tests

永井 泰樹; 川端 方子; 佐藤 望; 橋本 和幸; 佐伯 秀也; 本石 章司*

Journal of the Physical Society of Japan, 83(8), p.083201_1 - 083201_4, 2014/07

https://doi.org/10.7566/JPSJ.83.083201

High thermo-separation efficiencies of about 90% and 70% have been obtained for the first time for Tc from molten MoO samples containing Mo with thicknesses of 4.0 and 8.8 mm, respectively, by repeated milking tests. Mo was produced with Mo(,2)Mo by using neutrons from H(,)He. The thermo-separation efficiency was determined by measuring the 141 keV -ray yield of Tc within the molten MoO samples with a radiation detector as a function of the furnace temperature and time. The diffusion coefficients of Tc in the molten MoO samples were estimated in order to help understand the Tc release mechanism. The present result solves a long-standing problem of decreasing the separation efficiency of Tc from MoO while increasing the sample mass or repeating sublimation in thermo-separation, and will bring a major breakthrough to obtain high-quality Tc from MoO irradiated by accelerator-neutrons (protons) or reactor-neutrons.