The present invention provides a lamp device comprising: a glass tube configured to cover a discharge space in which a pair of electrodes are arranged so as to face each other; and a bayonet cap portion provided in an end portion of the glass tube and electrically connected to one electrode of the pair of electrodes, wherein the bayonet cap portion is formed to have a shape including a bottom surface and a peripheral surface, and includes, in the bottom surface, a first opening configured to supply a gas to an inside of the bayonet cap portion and a second opening configured to exhaust the gas from the inside of the bayonet cap portion.

A radiation source assembly comprises a source base, a UV transparent sleeve, and a UV lamp. The source base comprises a sealed electrical connection interface and an opposing sealed sleeve interface. The sealed electrical connection interface comprises a electrical contacts and the sealed sleeve interface comprise a radial sealing element, an outer collar, and a compression ring. The UV transparent sleeve is engaged with the sleeve interface such that the radial sealing element of the sealed sleeve interface is disposed between the UV transparent sleeve and the outer collar of the source base, and the compression ring is positioned over the UV transparent sleeve and engaged with the source base to compress the radial sealing element onto the UV transparent sleeve and the outer collar. The UV lamp is disposed within the UV transparent sleeve and electrically coupled to the electrical contacts of the electrical connection interface.

A glass-metal feedthrough includes: an external conductor having a coefficient of expansion α.sub.external, and having an opening formed therein; an internal conductor disposed in the opening, the internal conductor including iron and having a coefficient of expansion α.sub.internal, the external conductor and the internal conductor being configured to not release nickel when in contact with a human or animal body or biological cells of a cell culture; and a glass material surrounding the internal conductor within the opening and having a coefficient of expansion α.sub.glass, the coefficient of expansion of the internal conductor α.sub.internal and the coefficient of expansion of the external conductor α.sub.external are such that a joint pressure on the internal conductor of at least 30 MPa is generated in a temperature range of 20° C. to a glass transformation temperature of the glass material.

A flash discharge tube includes tungsten pins configuring a pair of discharge electrodes, and an envelope. The envelope includes a central region, serving as an alkali-free region, which is configured with an alkali-free glass except for quartz glass. The central region becomes in a high temperature state during a firing operation of the flash discharge tube. The central region is smaller than a maximum region enclosing a gas-tight space formed by hermetically sealing the pair of the discharge electrodes and is not smaller than a minimum region enclosing an arc-discharge space formed between the tungsten pins of the pair of the discharge electrodes. The alkali-free region contains either no alkali metal component or not larger than a predetermined amount of an alkali metal component. Then, a trigger electrode is disposed in the alkali-free region. This provides the flash discharge tube featuring a stable short-interval continuous-firing operation.

A ceramic metal halide lamp includes a luminous tube; an illuminating arrangement having at least two illuminators serially connected with each other and deposed inside the luminous tube; and at least one retainer having at least contacting one end being contacted with an inner surface of the luminous tube to support the illuminators being stability located at a predetermined position inside said luminous tube, wherein the two illuminators are serially connected with each other along a central line of said luminous tube.

Disclosed herein are a short arc type flash lamp having high lamp starting performance and capable of reducing the diameter of its seal tube part, and a light source device thereof. The flash lamp has an electrode shaft of one of the main electrodes, and an electrode shaft of the other of the main electrodes and leads for starting auxiliary electrodes which are respectively led out from the second seal tube part, and an external trigger is disposed in a state in which it extends in the circumferential direction on the outer peripheral surface of one end side region of the second seal tube part. The light source device is structured by a concave reflection mirror disposed on the second seal tube part side of the flash lamp in a state in which a focal point of the concave reflection mirror coincides with a luminous point of the flash lamp.

A glass-metal feedthrough includes: an external conductor including steel, having a coefficient of expansion α.sub.external, and having an opening formed therein; an internal conductor disposed in the opening, the internal conductor including steel and having a coefficient of expansion α.sub.internal. The external conductor and the internal conductor are configured to not release nickel when in contact with a human or animal body or biological cells of a cell culture. A glass material surrounds the internal conductor within the opening and has a coefficient of expansion α.sub.glass. The coefficient of expansion α.sub.external of the external conductor and the coefficient of expansion α.sub.internal of the internal conductor both are greater than the coefficient of expansion α.sub.glass of the glass material.

A glass-metal feedthrough includes: an external conductor having a coefficient of expansion α.sub.external, and having an opening formed therein; an internal conductor disposed in the opening, the internal conductor including iron and having a coefficient of expansion α.sub.internal, the external conductor and the internal conductor being configured to not release nickel when in contact with a human or animal body or biological cells of a cell culture; and a glass material surrounding the internal conductor within the opening and having a coefficient of expansion α.sub.glass, the coefficient of expansion of the internal conductor α.sub.internal and the coefficient of expansion of the external conductor α.sub.external are such that a joint pressure on the internal conductor of at least 30 MPa is generated in a temperature range of 20° C. to a glass transformation temperature of the glass material.

A flash lamp includes a bulb including a stein, conductive linear members extending to penetrate the stein, and a trigger probe having a discharging portion configured to control discharge, wherein the conductive linear member has a lead pin and an anode protruding toward the conductive linear member on a tip end side of the conductive linear member with respect to the lead pin, wherein the lead pin and the anode are integrally formed members, wherein the conductive linear member has a lead pin and a cathode protruding toward the conductive linear member on a tip end side of the conductive linear member with respect to the lead pin, wherein the lead pin and the cathode are integrally formed members, and wherein the discharging portion of the trigger probe is disposed between the anode and the cathode.

A glass-metal feedthrough consists of an external conductor, a glass material and an internal conductor. The internal conductor has a coefficient of expansion α.sub.internal, the glass material has a coefficient of expansion α.sub.glass, and the external conductor has a coefficient of expansion α.sub.external. The coefficient of expansion of the internal conductor α.sub.internal is greater than the coefficient of expansion of the glass material α.sub.glass and the coefficient of expansion of the external conductor α.sub.external is at least 2 ppm/K, such as at least 4 ppm/K, greater than the coefficient of expansion of the glass material α.sub.glass in the temperature range of 20° C. to the glass transformation temperature.