Abstract:
An electron source suitable for an electron beam exposure system, an Auger electronic spectrometer or the like, and provides a small total emission current amount even during a high-angular-current-density operation. An electron gun provided with a cathode (1) consisting of tungsten or molybdenum single crystal and provided on the surface thereof with a coating layer consisting of oxygen and at least one kind of metal element selected from a group consisting of 2A group, 3A group and 4A group, characterized in that the end of the cathode (1) has a conical trapezoid shape, a total conical angle of a conical trapezoid portion (8) is between 25° and 95°, and the diameter of the top face (9) is 5mum through 200mum.
Abstract:
A tungsten wire containing 1 to 10% by mass of rhenium has a point which indicates a 2% elongation within a quadrangle formed by joining points with straight lines, where the values of x and y are point (20, 75), point (20, 87), point (90, 75), and point (90, 58), in this order, wherein the wire diameter of the aforementioned tungsten wire is represented by x µm, and the elongation of the tungsten wire is 2% after electrically heating with an electrical current which is a ratio of y% to the fusion current (FC) at the wire diameter x µm, and wherein a semi-logarithmic system of coordinates is expressed by a horizontal axis using a logarithmic scale of the aforementioned wire diameter x and a vertical axis using a normal scale of ratio y to the fusion current. According to the above-described configuration, a tungsten wire having a great elongation even under conditions of high temperature can be provided, and the tungsten wire can exhibit an excellent durability when used as component material for constituting cathode heaters and so forth, and the tungsten wire can be manufactured efficiently.
Abstract:
A thermionic electron emitter includes an electron emissive layer (5) formed solely of an alloy containing osmium in the proportion, expressed in atomic percent, in the range from 32 percent to 34 percent inclusive, the balance being of tungsten, and a porous refractory medium (4) impregnated with an alkaline earth activator (FIG.2). In another example the activator is confined on the side of the medium remote from the layer (FIG.3). Alternatively (FIG.4) the layer is porous and is impregnated with the activator, or the activator is confined on the side of the porous layer remote from the electron emissive surface thereof (FIG.5).
Abstract:
It is an object to provide a tungsten alloy containing no thorium which is a radioactive material, which is equal to or higher in emission characteristics than a thorium-containing tungsten alloy, and a discharge lamp, a transmitting tube and a magnetron which use the tungsten alloy. According to one embodiment, a tungsten alloy includes a Hf component within a range of 0.1 wt% or more and 3 wt% or less in terms of HfO 2 .
Abstract:
An electron emissive composition comprises a barium tantalate composition of the formula (Ba 1-x , Ca x , Sr p , D q ) 6 (Ta 1-y , W y , E t , F u , G v , Ca w ) 2 O (11 ± δ) where δ is an amount of about 0 to about -3; and wherein D is either an alkali earth metal ion or an alkaline earth ion; E, F, and G, are alkaline earth ions and/or transition metal ion; x is an amount of up to about 0.7; y is an amount of up to about 1; p and q are amounts of up to about 0.3; and t is an amount of about 0.05 to about 0.10, u is an amount of up to about 0.5, v is an amount of up to about 0.5 and w is an amount of up to about 0.25. A method for manufacturing an electron emissive composition comprises blending a barium tantalate composition with a binder; and sintering the barium tantalate composition with the binder at a temperature of about 1000°C to about 1700°C.
Abstract:
A cathode material of an electron beam device comprising 0.5 to 9.0 % by weight of a rare-earth metal of the cerium group, 0.5 to 15.0 % by weight of tungsten and/or rhenium, 0.5 to 10 % by weight of hafnium and the balance of iridium is provided. Since the cathode material has excellent plasticity, it is easy to manufacture small-size emitters. Also, since the density of the electron emission of the cathode material is high and the working temperature is low, a long lifetime can be ensured. Also, the cathode material is useful as a cathode material of an electron beam device.