Abstract: A high current density ion beam source includes a plasma source for generating plasma, a vacuum chamber coupled to the plasma source for extracting an ion beam from the plasma generated by the plasma source, a microwave field source configured to produce a microwave field that causes an ionization of gas within the plasma source, and a direct current voltage source configured to initiate an avalanche multiplication within the plasma source. The avalanche multiplication increases the ionization of gas in the plasma source and causes an increase in a current density of the ion beam.