Abstract: A discharge lamp of the short arc type with good light intensity stability in which arc fluctuation is suppressed is achieved, according to the invention by providing a discharge lamp of the short arc type which has an arc tube which surrounds the discharge space, hermetically sealed portions on the two ends of the arc tube, a cathode and an anode which are arranged opposite one another in the arc tube and which is operated such that the cathode is pointed upward, in by the cathode being supported by an inner lead which is held securely by the hermetically sealed portion, the outside diameter of the cathode being greater than the outside diameter of the inner lead, and by the relationship L.gtoreq.2.5D being satisfied, where D is the outside diameter of the cathode (mm) and L is the axial length of the cathode (mm).

Abstract: A surface activating process in which treatment can be performed within a short time and in which activation of undesired areas does not occur is achieved by concentrating ultraviolet light with wavelengths from 200 nm to 300 nm by means of an oval focussing mirror. The ultraviolet light is incident in parallel on a mask via a first reflector, an integrator lens, a shutter, a second reflector, and a collimator, and is radiated through the mask onto a workpiece to activation a surface area of the workpiece. The arc length of the lamp is selected to be within a range from 7.5 to 29 mm to obtain a radiation intensity which is sufficient for surface activation. Furthermore, the relationship .alpha.>1.5.degree. and the relationship d.times.tan .alpha..ltoreq.0.1 W are satisfied at the same time, where .alpha.

Abstract: A cadmium discharge lamp which can emit line spectra with wavelengths of 214.+-.2 nm with high power is achieved by encapsulating metallic cadmium, in an amount producing a pressure in stationary lighting operation in the range from 2 kPa to 13.7 kPa, together with at least one of the rare gases xenon, krypton, argon and neon, in a temperature-controlled arc tube which is provided with electrodes located adjacently opposite one another, and by operating the lamp such that J/P is in the range from 1.4 to 75, where J is the discharge current in stationary lighting operation in amperes and the P is the cadmium pressure in stationary lighting operation.

Abstract: An emission device which operates a cadmium lamp with a light intensity sufficient for used in industrial applications is achieved by an emission device having a cadmium lamp with a fluorescent tube within which a cathode and an anode are space a small distance apart and a buffer gas for easier initiation of luminous operation and metallic cadmium in an amount per unit volume of the fluorescent tube of 1.times.10.sup.-4 g/cm.sup.3 to 3.times.10.sup.-3 g/cm.sup.3 are encapsulated, and a power source device for supplying an electrical input between the cathode and the anode in an electrical input range from 0.5 kW to 5.0 kW with the condition:6.03+2.79 W.ltoreq.r.ltoreq.40being satisfied, where the electrical input of the power source device into the cadmium lamp in steady-state luminous operation is W (kW) and the maximum inside radius of the fluorescent tube is r (mm).

Abstract: A cadmium rare gas discharge lamp of the short arc type that has a high power of the spectra in a wavelength range of 210 nm to 230 nm and a stable lamp voltage in lighting operation for a long period. An arc tube 1 is provided within which are disposed opposed, spaced apart electrodes 2, 3 and thermal insulation films 6, 7. A rare gas is encapsulated together with metal cadmium and a quartz glass is used for the material of the arc tube whose OH radical has a weight content of no more than 200 ppm. Electrodes 4 and 5 are spaced apart no more than 10 mm, so that with a lamp current at least 20 amperes, an arc of the electrode-stable type is formed and radiant light of Cd ions obtained. For the encapsulated rare gas, in one embodiment at least one of the rare gases neon, argon or krypton, are used and are encapsulated at a gas pressure of 35 kPa to 2.5 MPa at a standard temperature of 25.degree. C. The arc tube 1 is formed of quartz glass, electrodes 2 and 3 are placed opposite one another.

Abstract: A discharge lamp uses resonance lines which are emitted by ions in an excitation state and has a high short wave ultraviolet ray output. The lamp is provided with a pair of electrodes, having a reciprocal spacing of equal to or smaller than 12 mm, and is of the electrode-stable type. As the major emission material, cadmium is encapsulated in a quantity permitting a partial pressure P in operation of 3.times.10.sup.3 Pa to 1.3.times.10.sup.5 Pa. The lighting operation is performed in a state in which a lamp current J.sub.L fulfills the following condition (a):0.7<J.sub.L /P.sup.1/4 <15.0. Condition (a)As an alternate major emission material, zinc can be encapsulated in a quantity permitting a partial pressure P in operation of 1.times.10.sup.3 Pa to 0.3.times.10.sup.5 Pa ant the lighting operation is performed in a state in which a lamp current J.sub.L fulfills the following condition (b):0.7<J.sub.L /P.sup.1/4 <16.9.

Abstract: A cadmium/inert gas discharge lamp of the short arc type, which suppresses an unnecessary emission upstream and downstream of the necessary emission spectra in a wavelength range of 210 to 230 nm, achieves a high efficiency of the emission spectra in the range 210 to 230 nm and can be used in very satisfactory manner for industrial applications. Also, a highly efficient projection exposure device through the incorporation of a cadmium/rare gas discharge lamp of the short arc type having good emission spectrum characteristics in the wavelength range 210 to 230 nm, which can transmit in projecting manner fine image patterns with a large depth of focus. The cadmium/rare gas discharge lamp of the short arc type is arranged within a temperature-regulated quartz bulb, and is provided with a pair of adjacently facing electrodes, together with inert gas selected from xenon, krypton, argon, neon or mixtures of them.

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).