Production of high pure 97Tc for environmental research

The complete procedure for producing pure 97Tc is described. The reaction 95Mo (4He,2n) 97Ru was used. The enriched 95Mo (> 90%) target (10 mg cm-2) was irradiated with 31.5 MeV 4He-ions for 70 h at 30 A. Obtained 97Ru decays (T1/2 = 2.9 d) with the formation of 97Tc (99.9%) and 97mTc (1.7 x 10-2 %). After a 100 day cooling the target was removed from the copper backing. The radiochemical procedure included dissolution of the target and subsequent distillation of 97Tc as Tc2O7 with HClO4. Over 98% of 97Tc were recovered after two distillations. Radioactive admixtures of 56,57,58Co, 54Mn, 65Zn produced from the copper backing were quantitatively retained in the precipitate in the distillation flask. The obtained quantity of 97Tc was 3.5 μg. According to the calculations it contained less than 0.18 μg of 95Mo and less than 0.0036 μg of 97Mo. (author)