Studies intended to optimize the production of Na18F, in aqueous solution following irradiation of organic fluorine compounds with 14 MeV neutrons are described. The use of Szilard-Chamers conditions was chosen to enhance the yield of18F, given the low fluxes available and the inherently low cross section of the (n, 2n) reaction. Twenty five potential target compounds were tested. The most suitable one, both in terms of the cost of the target material and of the efficiency of production of water-soluble Na18F, was found to be perfluoro n-hexane. A simple production method for18F– is outlined.