كليدواژه :
Germanium-68 , Ga-68 , Radioisotope Generators , Isotope Production
چكيده لاتين :
Ga-68 is a radioisotope material with a half life of 68 min. As it has a specific decay mode, it is a positron emitter and hence, is popularly used in nuclear medicine. The only way to obtain these nuclides is to produce the mother nuclease which is Germanium-68. There are many nuclear reactions from which the Ge-68 is obtained, however, the best reaction is 69Ga(p,2n)68Ge. The cross section of this nuclear reaction was calculated with the ALICE-91 Code and the result was compared with the practical work made by other researchers, and it was acceptable. Having the cross sections in mind, the best proton energy was calculated to be between 20-25 MeV. Further research showed that Ga2C>3 is the best type of target material. Therefore, it was necessary to design and make a suitable target holder for these kind of compositions, which for the first time in Iran was demonstrated in the Atomic Energy Organization of Iran (AEOI). The thickness of the target, bearing in mind the rate of energy loss inside the target material, was calculated with the SRIM Code and the Ga2O3 tablets were made with FT-IR facilities at the Nuclear Research Center for Agriculture and Medicine (NRCAM). They were, then bombarded with 22.5 MeV proton energy and the beam currents of 2 and 10 (mu)A. Two weeks after the bombardment the radio chemical separation of Ge-68 was accompolised with concentrated acid HNO3 and by applying heat. Then, the acid solution was evaporated till dried, after that, an EDTA solution (0.005 M, pH=11) was added to recover the Ge-68. By passing the EDTA solution with the rate of 0.5 ml/min through the A12O3 column, the Ge-68 radioisotope was observed. Then, about 50 ml of EDTA (0.005 M, pH=11) was passed through the loaded column, where almost all the natural Gallium impurities were removed. The prepared generators were milked many times with EDTA solution (0.005 M, pH=8) and the leakage of Ge-68 nuclease and natural Gallium were determined. The average of the mother nuclides (Ge-68) was about 0.03% and the natural Gallium was 0.7 (mu)gl^-1, which is compatible with the reports of other researchers.
