In-target production of [13N]ammonia: target design, products, and operating parameters.

[13N]Ammonia, commonly used in PET, has been prepared in good yield in the target. Up to 800 mCi of radiopharmaceutical was obtained by in-line processing of the irradiated water. Relatively low hydrogen pressure was used to control the target chemistry. Target designs and the product dependence on beam dose, dose rate and pressure are reported. Ethanol as a target additive was also investigated. Hydrogen and ethanol together were more effective than either alone at high beam dose. Parameters are reported for production needs from single doses to synthetic applications. An incidental method for production of [13N]nitrogen gas is also reported.