Electric discharge laser with two-material electrodes

A gas discharge laser comprising:

• A) a laser chamber containing a laser gas said laser gas comprising fluorine,
• B) two long life elongated electrode elements defining a cathode and an anode, each of said cathode and anode having a long narrow discharge region having a predetermined width chosen to define width of electric discharges between the electrode elements, said anode being comprised of:
• 1) a first anode material, defining a first anode erosion rate, located at said long narrow discharge region of said anode said discharge region defining two long edges, and
• 2) a second anode material located on at least two sides of said long narrow discharge region of said anode along said two long edges and adjacent to said long narrow discharge region of said anode,
• wherein said first and second anode material are chosen such that the second anode erosion rate is at least 0.50 percent greater than the first anode erosion rate,
• C) a pulse power system for providing electrical pulses at rates in excess of 1000 pulses per second to produce said electric discharges,
• D) a blower system for circulating said laser gas between said two electrodes at a velocity sufficient to remove substantially all debris produced by a discharge prior to a next subsequent discharge when operating at pulse rates in excess of 1000 pulses per second,
• E) a heat exchanger having sufficient capacity to remove heat from said laser gas produced by said blower system and said electric discharges,
• wherein during operation of said laser, greater erosion rate of said second anode material prevents any substantial long-term widening of said width of said discharges.