An ion source comprising: a chamber ; a first hollow cathode body having a first hollow cathode cavity and a first plasma exit orifice and a second hollow cathode body having a second hollow cathode cavity and a second plasma exit orifice , the first and second hollow cathode bodies 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 exit orifice and the chamber , wherein the second ion accelerator forms a second ion acceleration cavity , wherein the first hollow cathode body and the second hollow cathode body are configured to alternatively function as electrode and counter-electrode to generate a plasma, and wherein each of the first hollow cathode and second hollow cathode bodies in combination with the respective first and second ion acceleration cavities are configured to generate the necessary repulsive force for enabling the extraction and acceleration of ions without the presence of magnetic fields, wherein the first ion acceleration cavity comprises an integral part of the first hollow cathode body and/or the second ion acceleration cavity comprises an integral part of the second hollow cathode body , and characterized in that 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 . a chamber ; a first hollow cathode body having a first hollow cathode cavity and a first plasma exit orifice and a second hollow cathode body having a second hollow cathode cavity and a second plasma exit orifice , the first and second hollow cathode bodies 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 exit orifice and the chamber , wherein the second ion accelerator forms a second ion acceleration cavity , wherein the first hollow cathode body and the second hollow cathode body are configured to alternatively function as electrode and counter-electrode to generate a plasma, and wherein each of the first hollow cathode and second hollow cathode bodies in combination with the respective first and second ion acceleration cavities are configured to generate the necessary repulsive force for enabling the extraction and acceleration of ions without the presence of magnetic fields, wherein the first ion acceleration cavity comprises an integral part of the first hollow cathode body and/or the second ion acceleration cavity comprises an integral part of the second hollow cathode body , and characterized in that 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 . <EOS>