Abstract: In a metallic vapor discharge lamp, in whose arc tube provided with electrodes are encapsulated together with mercury and inert gas, whose quantity is adequate for maintaining arc discharges, an adequate quantity of iron and an adequate quantity of a metal, in which at least one of the metals tin, magnesium, bismuth, thallium, cadmium or manganese is selected, together with halogen, as a result of the fact that the encapsulated halogen at least contains bromine, whose weight ratio to the total halogen is 0.26%, the adhesion of iron to the inside of the arc tube is prevented and consequently a radiation intensity of the ultraviolet rays effective for curing paints or inks is maintained over a long period of time.

Abstract: A metal vapor discharge lamp comprises a light-emitting tube filled with bismuth together with mercury, a rare gas, iron and a halogen in the range of 1/20-6/1 in terms of the gram atom ratio of bismuth to iron (Bi/Fe). A metal vapor discharge lamp also comprises a long light-emitting tube having an inner diameter D of 18-35 mm, equipped with a pair of electrodes and having an electrode interval L of 750 mm or greater, filled with bismuth together with mercury in a sealed amount of 0.6-2.0 mg per cc of the internal volume of the light-emitting tube, a rare gas, iron and a halogen in the range of 1/20-6/1 in terms of the gram atom ratio of bismuth to iron (Bi/Fe).

Abstract: A metal vapor discharge lamp includes a light-emitting tubing in which a halogen and iron at least 0.005 mg per cc of the internal volume of the light-emitting tubing are filled together with mercury and a rare gas in amounts sufficient to retain a discharge. Magnesium is additionally filled in at a magnesium-to-iron ratio of 1/40-2/3 in terms of gram atom number so as to prevent iron from depositing on the inner wall of the light-emitting tubing and forming a thin film thereon.

Abstract: A magnesium vapor discharge lamp includes a light-emitting tubing in which magnesium and a halogen are sealed as light-emitting substances together with mercury and a rare gas in amounts sufficient to retain a discharge. Iron is additionally sealed within the light-emitting tubing.

Abstract: A semiconductor wafer can be exposed by arranging a combination of electrodes in an opposed relation with an interelectrode distance of not more than 15 mm in a closed discharge cavity, enclosing, within the cavity, mercury as a light-emitting discharge component in an amount such that the vapor pressure of mercury reaches 0.4-5 atms during discharge lighting, forming a discharge between the combination of electrodes while controlling the discharge current at not less than 10 A, and irradiating light, which has been radiated as a result of the discharge and contains at least one of light components having wave-lengths of 405 nm and 436 nm respectively, onto the surface of a photoresist applied on the semiconductor wafer through a photomask or reticle and a lens which permits transmission of the light having wavelength of 405 nm or 436 nm therethrough.