Presented are results on the modelling of a cascaded arc. Under suitable conditions, the plasma effusing out of the arc has a high degree of ionization. It is proposed to use this arc as the plasma source of a plasma neutralizer in neutral beam injectors for fusion research. The neutralization of a D−beam results in the generation of an electron beam. The power in thise‐beam is too small to sustain the plasma in the neutralizer for the 1.3 MeV fusion beams.