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.

The present disclosure describes a plasma illumination device with microwave pumping, comprising:

a hermetically sealed casing, a magnetron, a microwave resonator containing a rotatable electrodeless plasma lamp,

a coaxial coupling line running parallel to the casing axis, for transmitting microwave power from the magnetron to the microwave resonator, at least one heat sink located on the inner walls of the casing and providing heat transfer through the casing to the external environment, and a light-transmitting hermetically sealed hollow cylinder fitted in a hermetically sealed way on the casing above the microwave resonator. This results in an illumination device with microwave pumping, which may be used to illuminate objects located in unfavorable environmental conditions, particularly those in which there is a high content of dust or other contaminants, or in an aqueous environment at great depths.

The present disclosure describes a plasma illumination device with microwave pumping, comprising:

a hermetically sealed casing, a magnetron, a microwave resonator containing a rotatable electrodeless plasma lamp,

a coaxial coupling line running parallel to the casing axis, for transmitting microwave power from the magnetron to the microwave resonator, at least one heat sink located on the inner walls of the casing and providing heat transfer through the casing to the external environment, and a light-transmitting hermetically sealed hollow cylinder fitted in a hermetically sealed way on the casing above the microwave resonator. This results in an illumination device with microwave pumping, which may be used to illuminate objects located in unfavorable environmental conditions, particularly those in which there is a high content of dust or other contaminants, or in an aqueous environment at great depths.

An excimer lamp includes a housing portion having a sealed internal space, an internal electrode, and a discharge gas with which the internal space is filled. One end side of the internal electrode is electrically connected to a power supply member provided with a metal foil electrically connected to the internal electrode and is sealed together with the power supply member to one end side of the housing portion via a sealing portion. The other end side of the internal electrode protrudes into the internal space. A protrusion length, being a length of the internal electrode in the internal space and a length from one end of the internal space to the other end of the internal electrode, is equal to or less than a length from the other end of the internal electrode to the other end of the internal space in a direction along the axis.

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.

In the excimer lamp according to the present invention, a flat discharge vessel having a substantially rectangular cross-sectional shape and comprising a pair of planar parts and a pair of side-surface parts has a pair of external electrodes disposed on the respective outer surfaces of the planar parts. The end parts of the external electrodes are provided with an auxiliary electrode extending to a region that is made smaller than the distance between the planar parts. A lead that supplies electricity to the external electrode is connected to the auxiliary electrode in the region that is made smaller than the distance between the planar parts.

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.