There is provided a photoreactor for the remediation of gaseous emissions and/or contaminated water using ultraviolet (UV) or vacuum ultraviolet (VUV). There is also provided an emission source for generating UV and/or VUV, the source comprising: a microwave generator; a chamber arranged to receive microwaves generated by the microwave generator, the chamber comprising: a gas comprising species for forming excimers; a resonator arranged to receive the microwaves in the chamber and generate a plasma; a first electrode spaced apart from the resonator; and a voltage source configured to generate an electric field between the resonator and the first electrode, wherein, on application of the electric field, the electric field drives electrons and/or ions from the plasma to generate excimers and produce vacuum ultraviolet or ultraviolet emission. There are also provided methods of generating UV and/or VUV, and methods of remediating fluids.

A VUV excimer lamp has a dielectric tube for holding an excimer-forming gas, a first electrode disposed within the dielectric tube, and a second electrode arranged outside of the dielectric tube. The first electrode has an outer diameter less than 0.5 mm, is elongated, and includes at least one thin wire with an outer diameter between 0.02 mm and 0.4 mm. The thin wire is an elongated thin wire, and is substantially straight and defines a straight axis of elongation. A photochemical system has the VUV excimer lamp. An excimer lamp system has the VUV excimer lamp, and also has a power supply to supply AC electric power to the first electrode and the second electrode.

A VUV excimer lamp has a dielectric tube for holding an excimer-forming gas, a first electrode disposed within the dielectric tube, and a second electrode arranged outside of the dielectric tube. The first electrode has an outer diameter less than 0.5 mm, is elongated, and includes at least one thin wire with an outer diameter between 0.02 mm and 0.4 mm. The thin wire is an elongated thin wire, and is substantially straight and defines a straight axis of elongation. A photochemical system has the VUV excimer lamp. An excimer lamp system has the VUV excimer lamp, and also has a power supply to supply AC electric power to the first electrode and the second electrode.

A dielectric barrier VUV excimer lamp has an elongated dielectric tube for holding an excimer-forming gas, a first electrode disposed within the dielectric tube, and a second electrode arranged outside of the dielectric tube. The first electrode is a wire electrode disposed along a centre axis of the dielectric tube, axially symmetric with respect to the centre axis, and physically connected to each end of the dielectric tube. The dielectric barrier VUV excimer lamp is an AC dielectric barrier discharge VUV excimer lamp or the dielectric barrier VUV excimer lamp is a pulsed DC dielectric barrier discharge VUV excimer lamp. A photochemical system has the dielectric barrier VUV excimer lamp. An excimer lamp system has the dielectric barrier VUV excimer lamp, and also has a power supply to supply electric power to the first electrode and the second electrode.

A dielectric barrier VUV excimer lamp has an elongated dielectric tube for holding an excimer-forming gas, a first electrode disposed within the dielectric tube, and a second electrode arranged outside of the dielectric tube. The first electrode is a wire electrode disposed along a centre axis of the dielectric tube, axially symmetric with respect to the centre axis, and physically connected to each end of the dielectric tube. The dielectric barrier VUV excimer lamp is an AC dielectric barrier discharge VUV excimer lamp or the dielectric barrier VUV excimer lamp is a pulsed DC dielectric barrier discharge VUV excimer lamp. A photochemical system has the dielectric barrier VUV excimer lamp. An excimer lamp system has the dielectric barrier VUV excimer lamp, and also has a power supply to supply electric power to the first electrode and the second electrode.

An extreme ultraviolet light source apparatus includes a disc-shaped cathode rotating about an axis, a disc-shaped anode rotating about an axis, an energy beam irradiation device irradiating a plasma raw material on the cathode with an energy beam to vaporize the plasma raw material, a power supply for causing a discharge between the cathode and the anode for generating a plasma in the gap between the cathode and the anode to emit extreme ultraviolet light, and an irradiation position adjusting mechanism for adjusting a position at which the cathode is irradiated with the energy beam. The cathode, the anode, and the irradiation position adjusting mechanism are accommodated in a housing. A photography device is disposed outside the housing and is configured to photograph a visible-light image of a vicinity of the cathode and the anode, the vicinity including visible light emitted from the plasma.

An extreme ultraviolet light source apparatus includes a disc-shaped cathode rotating about an axis, a disc-shaped anode rotating about an axis, an energy beam irradiation device irradiating a plasma raw material on the cathode with an energy beam to vaporize the plasma raw material, a power supply for causing a discharge between the cathode and the anode for generating a plasma in the gap between the cathode and the anode to emit extreme ultraviolet light, and an irradiation position adjusting mechanism for adjusting a position at which the cathode is irradiated with the energy beam. The cathode, the anode, and the irradiation position adjusting mechanism are accommodated in a housing. A photography device is disposed outside the housing and is configured to photograph a visible-light image of a vicinity of the cathode and the anode, the vicinity including visible light emitted from the plasma.

A short-arc discharge lamp includes a pair of electrodes disposed facing each other inside a light-emitting tube, a scale-like structure being formed on an outer surface of at least one electrode of the pair of electrodes, and a coating film covering the outer surface on which the scale-like structure is formed. The scale-like structure includes a plurality of flaky protrusions protruding from the outer surface in a direction inclined with respect to a normal direction of the outer surface, each flaky protrusion having a front surface whose angle formed with the outer surface is an obtuse angle and a back surface whose angle formed with the outer surface is an acute angle. The coating film contains at least one of metal oxides, metal carbides, metal borides, metal silicides, and metal nitrides. A part of the coating film enters a space sandwiched between the back surface and the outer surface.

A short-arc discharge lamp includes a pair of electrodes disposed facing each other inside a light-emitting tube, a scale-like structure being formed on an outer surface of at least one electrode of the pair of electrodes, and a coating film covering the outer surface on which the scale-like structure is formed. The scale-like structure includes a plurality of flaky protrusions protruding from the outer surface in a direction inclined with respect to a normal direction of the outer surface, each flaky protrusion having a front surface whose angle formed with the outer surface is an obtuse angle and a back surface whose angle formed with the outer surface is an acute angle. The coating film contains at least one of metal oxides, metal carbides, metal borides, metal silicides, and metal nitrides. A part of the coating film enters a space sandwiched between the back surface and the outer surface.

There are provided a glass tube in which a rare gas under predetermined pressure is sealed, a cathode electrode and an anode electrode disposed in a first end portion and a second end portion of the glass tube, respectively, facing each other, and a trigger electrode including a transparent conductive film formed on an outer peripheral surface of the glass tube. The trigger electrode includes an electrode body disposed on the outer peripheral surface of the glass tube, along a tube axis direction of the glass tube, and an enlarged portion that covers at least any one of the cathode electrode and the anode electrode, and that has a circumferential width wider than a circumferential width of the electrode body. This provides a flash discharge tube capable of reducing variations in optical distribution characteristics during light emission with a small amount of light, and improving life durability during continuous emission of a large amount of light and at short intervals.