Method of extracting and accelerating ions

A method of extracting and accelerating ions comprising:

• (i) providing a ion source comprising:
• a chamber;
• a first hollow cathode having a first hollow cathode cavity and a first plasma exit orifice and a second hollow cathode having a second hollow cathode cavity and a second plasma exit orifice, the first and second hollow cathodes being disposed adjacently in the chamber;
• a first ion accelerator between and in communication with the first plasma exit orifice and the chamber, wherein the first ion accelerator forms a first ion acceleration cavity;
• and
• a second ion accelerator between and in communication with the second plasma orifice and the chamber, wherein the second ion accelerator forms a second ion acceleration cavity;
• wherein a width of the first ion acceleration cavity is larger than a width of the first plasma exit orifice, and a width of the second ion acceleration cavity is larger than a width of the second plasma exit orifice;
• (ii) generating a plasma within the first hollow cathode and the second hollow cathode, wherein the first hollow cathode and the second hollow cathode are configured to alternatively function as electrode and counter-electrode;
• and
• (iii) extracting and accelerating ions from the first hollow cathode and the second hollow cathode through the first ion acceleration cavity and the second ion acceleration cavity;
• wherein each of the first ion acceleration cavity and the second ion acceleration cavity are sufficient to enable the extraction and acceleration of ions without the presence of magnetic fields.