Development of a 50 kV hydrogen-helium mixed ion beam implanter

Ion implanters have extensively been employed to simulate the irradiation effects of neutrons on relevant nuclear materials. In this study, a 50 kV hydrogen-helium mixed ion beam implanter was developed to generate H2+ and He+ ion beams, with a beam current of 20 µA, while keeping the impurity ion content below 2%. The ions are generated by an antenna-type 2.45 GHz electron cyclotron resonance ion source, and the hydrogen-to-helium ion beam ratio was controlled using two gas mass flow controllers to ensure long time stability of the beam current. As a result, the H2+/He+ ratio, beam size, and homogeneity of the beam spot can be maintained at a stable level. The beam line consisted of four Wien filters, a movable dual-slit plate, and an accelerator tube. The experimental results demonstrated successful transport of more than 20 µA of H2+ and He+ ion beams onto the target, with a beam axis deviation of less than 0.5 mm.