Production of Medical Radionuclides with a 24 MeV Proton Cyclotron

The CGR-MeV 520 cyclotron of Ghent University is used for the production of radionuclides for medical use. The radionuclides and simple labeled molecules produced are : 81Rb, 13NH3, 38K and 11CO2. The 82Kr(p,2n) 81Rb reaction on natural krypton gas is used to produce 81Rb. The entire procedure is remote-controlled. 13NH3 is obtained by irradiation of water with 21 MeV protons, using the 16O(p,α)13N reaction. The 13N-containing nitrates and nitrites are reduced to 13NH3 with Devarda's alloy. 38K is obtained by irradiation of NaCl, of a saturated NaCl solution or of CCl4 with 21 MeV α-particles, according to the 35Cl(α,n) 38K reaction. To produce 11CO2, using the 14N(p,α) 11C reaction, N2 gas is irradiated with 18 NeV protons. The 11C combines with traces of O2 to yield 11CO2. 11CO2 is also used as a starting product for the synthesis of 11CH3I. This can be used as a precursor to label more complex organic molecules.