Thick Rhodium Plating as the Target for Cyclotron Production of Palladium-103

The preparation of rhodium target with high quality and thickness is the key to produce ¹⁰³Pd by cyclotron. In order to improve the thickness and quality of plating, rhodium sulfate solution is pretreated, and a certain amount of electroplating additives A is added. The target plate for ¹⁰³Pd is made of copper with a target size about 100 mm×10 mm. The optimal electroplating conditions are obtained according to the important conditions in the plating process (e.g., current density, plating temperature and H₂SO₄ concentration). In four consecutive batches of experiments, the mass thickness of the rhodium plating is higher than 150 mg/cm². In the thermal shock and falling test, the plating layer does not show problems such as flaking, and is tight, smooth and firmly bonded to the substrate. After irradiation in C30 cyclotron for 5-51.5 hours, ¹⁰³Pd nuclide with yield of 5.18-6.04 MBq/(μA·h) and nuclear purity greater than 99.9% can be obtained. The research solve the problem of poor stability of rhodium target preparation process by pulse electroplating, the quality of rhodium^target can meet the requirements of ¹⁰³Pd production.