Preparation of18F source for slow positron beam by proton bombardment of18O-water

Fluorine-18 produced by the18O(p,n)18F reaction on18O-water has proved to be highly useful as a source for a slow positron beam. About 70 GBq of18F is produced routinely by an ultra-compact cyclotron. The18F formed in H218O target is sent through a fine pipe to the site of positron slowing-down, fixed on a small spot by adsorption or drying, and then placed close to the moderator foil. An automatic apparatus has been set up for the entire process including the recovery of H218O.