Production of nitrogen-13 labeled ammonia in liquid niobium target at the Karaj cyclotron

A common and routine method for producing nitrogen-13 is 16O (p, α) 13N reaction, where nitrogen-13 is produced with the bombardment of O-16 through the induced proton, and is accompanied by emission of α-particles. Target material for N-13 production is pure water. The first experiment is carried out with a gold target. Because of the gold reaction with nitrogen-13, labeled ammonia (Au++n 13NH3=Au(13NH3)+n), a new liquid target made of niobium, was designed to overcom this drawback. One of the advantages of niobium element is its high chemical resistivity. The 13N radioisotope was produced at the Agricultural, Medical and Industrial Research School (AMIRS), where the target was irradiated with proton particles of 17.5 MeV energy and the current of 12 μA for 20 min. The yield of the radioisotope was about 84.5 mCi/μA h.