Production of 99Mo-99mTc by using spallation neutron

Objectives The 99mTc is one of necessary radioisotopes which is used most worldwide in the radioisotope examination today. However, the most are made with nuclear reactors, and understock by the deterioration of a used nuclear reactor is pointed out so far. Using cyclotrons, production of the 99mTc by the 100Mo(p,2n)99mTc and 100Mo(p,d)99Mo-99mTc reactions has been tried until now.

Methods We produced the 99mTc by the 100Mo(n, 2n)99Mo-99mTc reaction using spallation neutron which was produced by using 400 MeV proton from ring cyclotron at the Research Center for Nuclear Physics, Osaka University. A combination of chemical separation and nuclear reaction by spallation neutron using the 400 MeV proton from the cyclotron allowed production of Tc -99m necessary for radioisotope examination. We examined various metal targets to get most suitable spallation neutron flux. Further, some molybdenum targets were irradiated for the chemical separation of technetium from the target.

Results The irradiated molybdenum target was dissolved into aqueous solution. Tc-99m was separated by precipitation of molybdenum, and further impurities were removed by ion exchange chromatography. As a result of having irradiated natural molybdenum in spallation neutron by the proton of 400MeV from the cyclotron, the radioactivity of provided 99Mo-99mTc was 3MBq/gμAh.

Conclusions We produced the 99Mo-99mTc which radioisotope examination could use using narural molybdenum target. In addition, the impurities which occurred by spallation neutron reaction were removed by chemical separation. We shall discuss the yields of spallation neutron, produced radioactivity of 99Mo-99mTc and the removal of impurities by the chemical separation in the lecture