A method of extracting and accelerating ions is provided. The method includes providing a ion source. The ion source includes a chamber. The ion source further includes 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. The ion source further includes a first ion accelerator between and in communication with the first plasma exit orifice and the chamber. The first ion accelerator forms a first ion acceleration cavity. The ion source further includes a second ion accelerator between and in communication with the second plasma orifice and the chamber. The second ion accelerator forms a second ion acceleration cavity. The method further includes generating a plasma using the first hollow cathode and the second hollow cathode. The first hollow cathode and the second hollow cathode are configured to alternatively function as electrode and counter-electrode. The method further includes extracting and accelerating ions. Each of the first ion acceleration cavity and the second ion acceleration cavity are sufficient to enable the extraction and acceleration of ions.