Provided is a light source apparatus and an electrode design for use in a discharge chamber of the light source apparatus. The discharge chamber is configured to hold a gas discharge medium configured to output a light beam. The light source apparatus include a pair of opposed electrodes configured to excite a gas medium to form a discharge plasma. At least one electrode of the pair of opposing electrodes may include recessed portions or hollowed-out portions at each end of the electrode, or at other suitable locations. The disclosed electrode structures improve uniformity of the erosion profile of the electrodes, significantly extending the lifespan of the discharge chamber by redistributing the discharge particle flux through the electrode with an optimized design of the electrode geometry, as the local discharge particle flux is reduced at the recessed portions.

A laser chamber for a discharge excited gas laser apparatus may include: a first discharge electrode disposed in the laser chamber; a second discharge electrode disposed to face the first discharge electrode in the laser chamber; a fan configured to flow laser gas between the first discharge electrode and the second discharge electrode; a first insulating member disposed upstream and downstream of a laser gas flow from the first discharge electrode; a metallic damper member disposed upstream of the laser gas flow from the second discharge electrode; and a second insulating member disposed downstream of the laser gas flow from the second discharge electrode.

A discharge chamber for a deep ultraviolet (DUV) light source includes a housing; and a first electrode and a second electrode in the housing, the first electrode and the second electrode being separated from each other to form a discharge region between the first electrode and the second electrode, the discharge region being configured to receive a gain medium including at least one noble gas and a halogen gas. At least one of the first electrode and the second electrode includes a metal alloy including more than 33% and less than 50% zinc by weight.

A plasma heating apparatus including a boiler vessel for holding water to be heated, a cathode housed in the vessel, the cathode defining a watertight cathode chamber isolated from the water in the vessel, and, an anode housed in the cathode chamber, the anode including an internal passage for receiving a gas from outside of the vessel when the passage is connected to a gas supply, and wherein the anode is connectable to a power source for receiving power for generating a plasma in the cathode chamber. In another aspect, the present disclosure relates to a heat or power generating system or plant including the plasma heating apparatus.

Discharge electrodes include a cathode and an anode. The anode is disposed to face the cathode in a discharge direction perpendicular to a longitudinal direction of the cathode, and includes an electrode base 1, and a coating layer that covers a portion of a surface of the electrode base. First corners in a cross section perpendicular to the longitudinal direction connect first straight sections formed of first side surfaces that are side surfaces of the electrode base to a first curved section formed of a first discharge surface that is a discharge surface of the electrode base. The first corners are closer to the cathode in the discharge direction than second corners connecting second straight sections formed of second side surfaces that are side surfaces of the coating layer to a second curved section formed of a second discharge surface that is a discharge surface of the coating layer.

An apparatus for a light source includes: an electrical insulator that defines a channel; a gasket that surrounds at least a portion of the electrical insulator; and a shield between the channel and the gasket. The channel is configured to receive an electrical conductor. The gasket includes a non-metallic material.

Disclosed are methods of and apparatus for extending a useful lifetime of a laser discharge chamber in which a polarity of an electrode positioned at a fixed position within the chamber is caused to be positive with respect to the polarity of a second electrode defining a discharge gap with the first electrode and the first electrode is made of a material that forms an erosion resistant surface when the first electrode is used and an anode. Also disclosed is an arrangement in which a first electrode is positionable with respect a second electrode defining a discharge gap with the second electrode and the position of the first electrode controlled to maintain the width of the gap within a predetermined range.

A discharge chamber for a deep ultraviolet (DUV) light source includes a housing; and a first electrode and a second electrode in the housing, the first electrode and the second electrode being separated from each other to form a discharge region between the first electrode and the second electrode, the discharge region being configured to receive a gain medium including at least one noble gas and a halogen gas. At least one of the first electrode and the second electrode includes a metal alloy including more than 33% and less than 50% zinc by weight.

A positive high-voltage laser having a super-long discharge tube, including a gas storage tube having two ends respectively provided with a reflecting mirror and a light emitting surface; a water cooling tube in the gas storage tube; and a discharge tube inside the water cooling tube having two ends, each provided with an electrode. A liquid circulation space is between the discharge tube and the water cooling tube, and the water cooling tube extends outside the gas storage tube by water inlet and outlet tubes. A cathode is in a cathode chamber at the end of the discharge tube closest to the light emitting surface; a spiral gas return tube communicates with the cathode chamber; an anode circumscribes the outside of the water cooling tube at the other end of the discharge tube. The positive high-voltage laser can increase power with a limited length.

A discharge chamber for a deep ultraviolet (DUV) light source includes a housing; and a first electrode and a second electrode in the housing, the first electrode and the second electrode being separated from each other to form a discharge region between the first electrode and the second electrode, the discharge region being configured to receive a gain medium including at least one noble gas and a halogen gas. At least one of the first electrode and the second electrode includes a metal alloy including more than 33% and less than 50% zinc by weight.