Perforated wall hollow-cathode ion laser

An electrode structure for use in a gas-ion laser apparatus including a laser enclosure and means for introducing a gas flow at a predetermined pressure through the interior of said enclosure comprising:

• hollow cathode means, focusing electrode means, and auxiliary anode means positioned within said enclosure:
• said cathode means being in the shape of a hollow structure having at least one aperture, said cathode means being constructed from a material that is highly porous to electron-ion plasma;
• said focusing electrode means attached to said cathode means, surrounding the aperture of said cathode means and extending outward therefrom for focusing an electronion beam emanating therefrom;
• said auxiliary anode means located in the general vicinity of said cathode means;
• and
• connection means for supplying operating potential to said cathode means and to said auxiliary anode means.

A method of generating a laser beam in a gas-ion laser apparatus including a laser enclosure with a laser axis running therethrough;

• a hollow cathode structure within said enclosure having at least one aperture substantially aligned along said laser axis of said enclosure;
• an auxiliary anode structure located in the general vicinity of said cathode structure and having at least one anode aperture, said anode aperture being larger than and substantially aligned with said cathode aperture;
• an accelerating anode located along said laser axis facing said cathode aperture, said accelerating anode having an aperture through which said laser beam may pass;
• and
• optical feedback means substantially aligned along said laser axis, said method comprising the steps of:
• introducing a lasing gas flow at a particular pressure into said enclosure;
• generating a high energy electron beam having a velocity distribution that is high enough so that most of the electrons in said electron beam are capable of causing lasing gas ionization and excitation by applying a highly negative voltage to said cathode structure and a positive voltage to said auxiliary anode structure, and maintaining an electric field between said cathode and said accelerating anode by applying a positive potential between said accelerating anode and said cathode so that said electron beam emanates from said cathode aperture;
• ionizing and exciting to an upper energy state said gas by collisions with the electrons of said plasma beam;
• and
• maintaining a laser beam by optical feedback from said optical feedback means.

An improved gas laser device having a laser enclosure;

• means for introducing a flow of noble gas at a predetermined pressure;
• means for generating a high energy electron beam capable of causing a population inversion in said noble gas sufficient to generate a laser beam;
• an accelerating electrode structure aligned with said electron beam generating means for drawing out and for accelerating said electron beam, said electrode structure having connections for supplying to said accelerating electrode structure a positive potential;
• a secondary anode electrode structure aligned with said electron-beam generating means for collecting said electrons of said electron beam;
• and
• connections for supplying to said anode structure a positive potential whose value is less positive than potential applied to said accelerating electrode.

A method for accelerating and collecting an electron beam in a laser device having a laser enclosure with a laser axis running therethrough, an accelerating electrode positioned along said laser axis, and a secondary anode for collecting the electrons from said electron beam, said method comprising the steps of:

• introducing a gas suitable for lasing into said laser enclosure at a predetermined pressure;
• generating an electron-ion plasma from said gas in said enclosure;
• applying a positive potential to said accelerating electrode for drawing out and accelerating an electron beam from said plasma along said laser axis;
• and
• applying a lower positive potential to said secondary anode, said lower potential being less positive than said potential applied to said accelerating electrode.

An electron-plasma beam focusing device for focusing an electron plasma beam along a beam axis within a gas filled enclosure comprising:

• a cold mesh-type hollow cathode structure having a pair of opposed openings aligned with said beam axis therein which are larger than the aperture in said mesh and are suitable for passing an electron-plasma beam therethrough;
• a focusing electrode electrically connected and attached to said cathode and arranged generally symmetric about said beam axis;
• an auxiliary anode located generally near said cathode;
• connections to said auxiliary anode and cathode for supplying a potential to said auxiliary anode which is positive with respect to said cathode;
• an accelerating anode located on said beam axis having an opening therein through which a laser beam may pass;
• and
• connections for supplying a potential to said accelerating anode which is positive with respect to said auxiliary anode.