High-yield, low-pressure [18O] water targets of titanium and niobium for F-18 production on MC-17 cyclotrons

Large volume low-pressure targets were designed for use on the wide-beam Scanditronix MC-17 cyclotron. The design was optimized experimentally by construction of aluminum test targets. Final production targets were constructed of titanium and niobium. The targets tripled the routine production yield of the previous target, giving up to 90 GBq (2.5 Ci) of fluoride and essentially eliminated the need for periodic target maintenance. The final targets represent a considerable improvement. However, they have not performed as well as predicted, indicating that further improvement is possible.