ABSTRACT
A forced-convection gas target for the production of [11C]CH4 on a 13â¯MeV cyclotron was constructed and tested. A small fan was incorporated into the back of the target, which mixes the target gas during irradiation. The effect of the forced convection alone on the target operation and the [11C]CH4 yield was measured. Forced convection improved the target yield by up to 16 ± 4%. In addition, improvement in heat transfer of up to 70% was observed to be a function of fan speed. Operating with forced convection allowed delivery of 21% higher beam currents while still staying in the acceptable pressure rise during irradiation, providing a 25 ± 7% greater yield.
ABSTRACT
There is a lack of real-time continuous beam-diagnostic tools for medical cyclotrons due to high power deposition during proton irradiation. To overcome this limitation, we have developed a profile monitor that is capable of providing continuous feedback about beam shape and current in real time while it is inserted in the beam path. This enables users to optimize the beam profile and observe fluctuations in the beam over time with periodic insertion of the monitor.
