Excitation functions of 3he-particle induced nuclear reactions on natural chromium: Possibilities of production of 52Fe, 53Fe and 52Mn for medical use

Excitation functions were measured by the stacked-foil technique for ^natCr(³He, xn) ^52.53Fe and ^natCr (³He, pxn) ^52m.52g.54 Mn reactions from threshold to 36 MeV. Thin foils of a Cr/Ni-alloy (20% Cr, 73% Ni) were used as targets. Additionally, thin samples were prepared by electrolytic deposition of Cr on Au-backing. Thick target yields of ^52,53Fe and ⁵²Mn were calculated from the measured excitation functions. The optimum ³He-energy ranges for the production of ⁵²Fe, ⁵³Fe and ⁵²Mn were found to be E_3He= 36 —> 17 MeV, e3hc= 17 —> 7 MeV and E_3He = 36 —> 15 MeV, respectively, with the expected thick target yields of 1.3 MBq (35 µCi)/µAh for ⁵²Fe, 78 MBq (2.1 mCi)/ pAh for ⁵³Fe and 5.6 MBq (150 µCi)/µAh for ⁵²Mn. For a small scale production of ^52.53Fe and ⁵²Mn 1 mm thick chromium foils were irradiated at beam currents between 1 and 12 µA. The radioiron was separated by anion-exchange chromatography and the radiomanganese via adsorption on Fe(OH)₃ followed by purification with anion-exchange chromatography. In 1 h irradiations the experimental yields at 1 µA amounted to about 70% of the calculated values and at 12 µA to about 45%. For routine production at a nominal beam current of 5 µA experimental yields of about 3.7 MBq (0.1 mCi)/h ⁵²Fe, 220 MBq (5.8 mCi)/30 min ⁵³Fe and 14.8 MBq (0.4 mCi)/h ⁵²Mn can be expected.