Production of Mo/Tc generator using high specific activity of Mo recoiled out from nanoparticle target by the Mo(n,2n) Mo reaction

Mo(n,2n)Mo反応により金属ナノ粒子ターゲットから反跳により分離される高比放射能Moを利用したMo/Tcジェネレータの製造研究

初川 雄一; 塚田 和明  ; 橋本 和幸; 佐藤 哲也   ; 佐藤 望; 浅井 雅人  ; 豊嶋 厚史

Hatsukawa, Yuichi; Tsukada, Kazuaki; Hashimoto, Kazuyuki; Sato, Tetsuya; Sato, Nozomi; Asai, Masato; Toyoshima, Atsushi

高速中性子による医療RI, Moの生成を提案している。本研究では金属モリブデンナノ粒子を塩化カリウム粉末と加圧成形したものを中性子照射ターゲットとして利用し、高速中性子核反応により高い反跳エネルギーでナノ粒子ターゲットから飛び出したMoイオンを粉末混合ターゲットを溶解し遠心分離によって金属ナノ粒子と水溶液を分離することによりMoの単離に成功した。この金属ナノ粒子モリブデンより単離されたMoイオンをアルミナカラムに吸着させることにより簡易なMo/Tcジェネレータの作成に成功した。このMo/Tcジェネレータに毎日1mlの生理食塩水を注水することにより、4日間にわたりMoから生成したTc生理食塩水溶液を得ることができた。

We proposed and propel a Mo production project via the Mo(n,2n)Mo reaction using fast neutrons from accelerator. Only low specific radioactive Mo, however, can be obtained in this method. In our project, Tc would be extracted from low specific radioactive molybdenum irradiated target, and then technetium labeled compounds from the purified Tc will be synthesized and deliver to the end user. Although labeled technetium compounds would be available, small scale technetium generator is still required in medical facilities. In this paper, feasibility study of production of high specific radioactive Mo using Szilard-Chalmers reaction from molybdenum nanoparticle target with accelerator neutron reactions was carried out. As neutron irradiation target, molybdenum nanoparticles were prepared by grinding with potassium chloride (KCl) powder, then pressed into a 10mm diameter disk. About 1.2 gram of the Mo/KCl target which contained about 100 mg molybdenum nanoparticles was irradiated with accelerator neutrons for 5 hours. After fast irradiation, the Mo/KCl target was dissolved in pure water, then solution and molybdenum nanoparticles were separated by centrifuge method. The solution contained recoiled Mo ion by fast neutron reactions was poured into alumina column. About 7% of Mo produced in the Mo/KCl target was absorbed onto the alumina column. Technetium-99m was obtained by pouring saline solution through the alumina column of immobilized Mo.