An ion implanter may include an ion source, arranged to generate a continuous ion beam, a DC acceleration system, to accelerate the continuous ion beam, as well as an AC linear accelerator to receive the continuous ion beam and to output a bunched ion beam. The ion implanter may also include an energy spreading electrode assembly, to receive the bunched ion beam and to apply an RF voltage between a plurality of electrodes of the energy spreading electrode assembly, along a local direction of propagation of the bunched ion beam.