Abstract:
A gas discharge lamp has a tubular envelope containing tubular electrodes at opposite ends. An annular support member of a compressible ceramic fiber is supported in a groove around each electrode and is compressed against the inside surface of the envelope. Movement of the electrodes relative to the envelope is damped by the support member.
Abstract:
Novel emitter materials, electrode assemblies amd lamps comprising the same are provided in which, in accordance with the invention, novel electrodes are provided having a lamp electrode structure, preferably including a hollow ferrule for sealing in a lamp to permit evacuation; an emitter material of the invention on at least one surface thereof, preferably on a protrusion attached to the hollow ferrule; a thermal isolator, preferably in the form of a low thermal conductivity wire or an incised or cut-out portion of the hollow ferrule body, for thermally isolating the protrusion from the ferrule to maintain a sufficiently high temperature for thermionic emission, and further comprising an emitter material requiring no in-lamp processing. The emitter materials are a mixed oxide of Ba, Sr and mixtures thereof with one or more of the metals from the series comprising Ta, Ti, Zr, Sc, Y, and La, are preferably selected from the group consisting of Ba.sub.4 Ta.sub.2 O.sub.9, Ba.sub.5 Ta.sub.4 O.sub.15, BaY.sub.2 O.sub.4, BaCeO.sub.3, Ba.sub.x Sr.sub.1-x Y.sub.2 O.sub.4, Ba.sub.2 TiO.sub.4, BaZrO.sub.3, Ba.sub.x Sr.sub.1-x TiO.sub.3, and Ba.sub.x Sr.sub.1-x ZrO.sub.3, wherein x ranges from a value of 0 to 1, and are most preferably one or more mixed oxides selected from the group consisting of Ba.sub.4 Ta.sub.2 O.sub.9, BaY.sub.2 O.sub.4, BaCeO.sub.3, Ba.sub.0.5 Sr.sub.0.5 Y.sub.2 O.sub.4, Ba.sub.0.75 Sr.sub.0.25 Y.sub.2 O.sub.4, Ba.sub.2 TiO.sub.4, BaZrO.sub.3, Ba.sub.0.5 Sr.sub.0.5 TiO.sub.3, and Ba.sub.0.5 Sr.sub.0.5 ZrO.sub.3.
Abstract:
An electric gas discharge lamp includes an electrode having a tip portion comprised by a mesh body carrying an emitter material. The mesh body in a favorable embodiment is circular cylindrical and is attached via an electrically conductive thermal isolator to a conductive feed-through, such as a hollow ferrule, extending through a seal of the lamp vessel. As compared to a continuous walled tip portion of similar shape and material, the mesh body has a lower mass and heat capacity, and can therefore be operated at higher temperatures without increasing the temperature of the seal area. The higher operating temperature of the tip portion promotes greater electron emission from the emitter material, and therefore a lower cathode fall. A lower cathode fall enables the lamp to be operated at higher lamp currents for greater light output. The mesh body also has the capability to reduce sputtering from the electrode through improved adhesion of the emitter material to the tip portion and faster attainment of its nominal operating temperature as compared to a smooth continuous walled body. In a favorable embodiment, the lamp is a low pressure discharge lamp having an inside diameter of less than about 5 mm.
Abstract:
A discharge device for operation in a gas at a prescribed pressure includes a cathode having a plurality of micro hollows therein, and an anode spaced from the cathode. Each of the micro hollows has dimensions selected to produce a micro hollow discharge at the prescribed pressure. Preferably, each of the micro hollows has a cross-sectional dimension that is on the order of the mean free path of electrons in the gas. Electrical energy is coupled to the cathode and the anode at a voltage and current for producing micro hollow discharges in each of the micro hollows in the cathode. The discharge device may include a discharge chamber for maintaining the prescribed pressure. A dielectric layer may be disposed on the cathode when the spacing between the cathode and the anode is greater than about the mean free path of electrons in the gas. Applications of the discharge device include fluorescent lamps, excimer lamps, flat fluorescent light sources, miniature gas lasers, electron sources and ion sources.
Abstract:
The low-pressure discharge lamp is discolsed having a lamp vessel into which hollow cylindrical electrodes enter, between which a discharge path extends. At least one of the electrodes has a tube at a distance from an end thereof, the tube extending in the discharge path. The tube is connected to the electrode by electrically conductive means and is coated with electron emissive material. The surface area of the material of the means in cross-section is at most 25% of the surface area of the material of the electrode in cross-section.
Abstract:
A hollow cathode type light source is provided having improved operating stability by forming the cathode of an alloy of a highly reactive, unstable prime metal of interest for spectral emission, and of a chemically stable, readily sputtered metal. An alloy of silver and calcium with a small amount of magnesium provides a hollow cathode device which exhibits stable operation after a minimum warm-up time.
Abstract:
A hollow-cathode gas-discharge tube comprises an anode and a cathode contained within a suitable envelope and isolated from one another, the cathode being provided with a cylindrical cavity having a diameter d, which is open on the side of the anode. The anode represents a hollow body of revolution arranged coaxially with the cathode cavity and composed of a hollow cylindrical portion mating a hollow variable-section portion. One portion of the anode represents a hollow cylindrical structure having a cavity diameter D, its bottom being provided with a central opening and disposed level with or below the end surface of the cathode. The other portion of the anode contains a cavity whose diameter evenly increases in the direction of emission from the cavity diameter D of the cylindrical portion of the anode, a height 1 of the cylindrical portion of the anode, its cavity diameter D, and the diameter d of the cylindrical cavity of the cathode being related to one another as follows:3d.ltoreq.1.ltoreq.6d2.ltoreq.D/d.ltoreq.4.
Abstract translation:中空阴极气体放电管包括阳极和阴极,其包含在合适的外壳内并彼此隔离,阴极设置有具有在阳极侧开口的直径d的圆柱形空腔。 阳极表示与阴极腔同轴布置的中空的旋转体,由与中空可变截面部分配合的中空圆柱形部分组成。 阳极的一部分表示具有空腔直径D的中空圆柱形结构,其底部设置有中心开口,并且设置在阴极端面处或下方。 阳极的另一部分包含一个空腔,其直径从阳极的圆柱形部分的空腔直径D,阳极的圆柱形部分的高度1,其空腔直径D和直径 阴极的圆柱形空腔的d相互相关,如下所示:3d = D / d = d / d。
Abstract:
In a device for the emission spectral analysis of samples, including an evaporating tube for receiving and thermally evaporating a sample, and a hollow cathode and anode for athermally exciting the evaporated sample, the evaporation tube forms said cathode. The anode and cathode are mounted adjacent one another in spaced apart relationship along the axis of the tube.
Abstract:
A type of spectral source lamp has a hollow cup-shaped cathode, the interior of which is coated with the spectrally emitting element or elements. A technique for forming such a coating of an alloy of an alkali metal (or metals), with, say, tin in the presence of some boron is proposed, (resulting in higher melting points and lower vapor pressures, thereby allowing higher operating lamp currents and consequent spectral radiation intensity). The coating material may be conformed directly on the interior of the cathode cup (say, of titanium) by fusing an alkali metal borohydride with tin, thereby avoiding the need to handle pure alkali metal. The hydrogen gas liberated during alloy formation removes some of the contaminants (e.g., oxides). A boron-containing, glassy slag may be readily separated from the alkali metal alloys. Specific examples in which the alkali metal component is sodium, potassium, or a mixture of sodium and potassium are disclosed. The other metal may be, for example, tin or lead.