Development of a nickel plated aluminum krypton-81m target system

A fully automated system was developed to produce rubidium-81 (⁸¹Rb), based on the ^natKr (p, n) ⁸¹Rb reaction. The energy incident on the target was 26MeV. Only 6MeV was stopped inside the gas and the remainder was stopped by a specially designed flange. The target body was characterized by its conical shape and its inner walls were chemically plated with 100±10µm of nickel (Ni). Ni is advantageous as a fairly good conductor of heat whose surface can resist solutions. Additionally, the Ni plated target allowed potassium chloride to dissolve ⁸¹Rb, with no further effect on the target body. The system produced ⁸¹Rb with a production yield of approximately 4.5mCi/µAh, which is close to the calculated expected yield of 5.3mCi/µAh. The system is able to deliver reliable and reproducible radioactivity for patients and can be operated up to 1500µAh before preventive maintenance is due. Key steps in designing the ⁸¹Rb target for selected energy ranges are reported here.