Process and apparatus for production of F-18 fluoride

#1. Technical Field

#The invention relates to production of an 18F radioisotope by means of proton irradiation of 18O enriched water.

#2. Background

#FIG. 1 is a schematic diagram of apparatus for practicing the invention;

#FIG. 2 is a graph of the reservoir vial and exchange cartridge radioactivity for two experimental runs;

#FIG. 3 is a graph of target water conductivity for the same runs as in FIG. 2; and

#FIG. 1 is a schematic diagram of the apparatus whose component parts will now be described. All of these are used in the field of High Pressure Liquid Chromatography (HPLC) where they are fairly common. Connections between components were made with either {fraction (1/16)} in. (1.6 mm) OD type 316 stainless steel tubing or {fraction (1/16)} in. (1.6 mm) OD, 0.030 in. (0.8 mm) ID polyetheretherketone (PEEK) tubing, as was mechanically convenient. The choice of tubing is believed to be not critical. PEEK compression fittings are used for both types of tubing.

#The target 11 is the standard “high yield” cyclotron target supplied by General Electric (U.S.) PET Systems AB (Uppsala, Sweden). This target has a silver body with an 0.8 ml target volume behind a 1 cm diameter circular aperture covered with a cobalt alloy Havar (TM) (Co 42.5%, Cr 20%, Ni 13%, Fe/W/Mo/Mn) foil sealed with a crushed silver o-ring. Using standard components (not illustrated), the target body is cooled by 20° C. water and the aperture foil is cooled with 50 psig (340 kPa) room temperature helium gas.

#Use of PEEK fittings means that the target is electrically insulated from the remainder of the apparatus. Thus, the beam current absorbed by the target material can be measured with an ammeter (not shown) connected between the target 11 and the cyclotron ground.