Production of 76Br by a low-energy cyclotron

We present a production method of a positron-emitting bromine isotope 76Br (T1/2=16.2 h) using a low-energy proton reaction 76Se(p, n)76Br. A pressed copper (I) selenide pellet containing enriched 76Se is used as a target. Irradiation of a 180 mg/cm2 target with 16→8 MeV protons gives a yield of 65–70 MBq/μAh EOB. In our target set-up with a simple water cooling, the target can withstand 14 μA. Bromine-76 is separated with an efficiency of 65–75%, within 60–75 min using dry distillation at 1090°C. The loss of target material is less than 1% per separation cycle and the target can be re-used several times. Thermal chromatography is applied to separate 76Br from traces of volatilized selenium. The method allows a simple and economical production of 76Br with the use of accelerators commonly available at PET-centers.