Metals suitable for fluorine gas target bodies: First use of aluminum for the production of [F-18]F-2

A comprehensive evaluation of different metals (aluminum, silver, copper, nickel, and gold plated copper) was undertaken for the fabrication of target bodies with straight and conical bore shapes for the production of [F-18]F-2 via the Ne-20(d,alpha)F-18 nuclear reaction. Of these metals, aluminum, silver and copper have never been used for the production of [F-18]F-2. All these target bodies were easily passivated using a mild beam-induced plasma technique in the presence of 1% F-2 in neon or argon. The recovery of F-18 activity was higher with electroformed nickel and silver bodies, probably due to favorable thermal conductivities. Aluminum proved to be a useful material for fluorine gas targets. The consistent recovery of F-18 activities, ease and low cost of manufacturing and low nuclear activation properties all make aluminum an ideal choice for fluorine gas targetry. To our knowledge, this investigation is the first to highlight the use of aluminum as a target body material for the routine production of [F-18]F-2. A reasonable mechanism based on the Langmuir-Rideal surface atom recombination is also proposed for the behavior of [F-18]F-2 recovery from a nickel target body.