Dual-reservoir remote loading water target system for (sup 18)F and (sup 13)N production with direct in-target liquid level sensing

摘要

This report describes our universal water target loading system that serves both ((sup 18)F) and ((sup 13)N) production targets, and a radionuclide delivery system that is specific for ((sup 18)F) fluoride. The system was designed and fabricated around the operation of a single pneumatic syringe dispenser that accesses one of two reservoirs filled with ((sup 18)O) enriched water for ((sup 18)F) fluoride production from the (sup 18)O(p,n)(sup 18)F reaction and natural abundance water for ((sup 13)N) nitrate/nitrite production from the (sup 16)O(p,(alpha))(sup 13)N reaction and loads one of two targets depending on the radionuclide desired. The system offers several novel features for reliable radionuclide production. First, there exists an in-target probe for direct liquid level sensing using the conductivity response of water. In addition, transfer of ((sup 18)F) fluoride to the Hot Lab is completely decoupled from the irradiated water through the actions of a resin/recovery system which is located in the cyclotron vault, thus maintaining transfer line integrity. This feature also provides a mechanism for vault-containment of long-lived contaminants generated through target activation and leaching into the water.