Abstract: An electric discharge tube or discharge lamp, in particular a flat-panel display screen, includes one or more low-temperature cathodes having a holder, which, optionally, is provided with a heating or cooling element, a conductive bottom layer which is applied to the holder, optionally a substrate with dispenser material, and a top coating of ultrafine particles having a nanostructure. The top coating has a surface layer consisting of an emitter complex formed from an emission material comprising several components. The cathodes have a high reliability and a long service life under a normal working load. The emission is stable, which contributes to a constant picture quality throughout the life of the discharge lamp or discharge tube. The discharge tubes or discharge lamps in accordance with the invention have short switching times and the advantage that their construction has been simplified and that their energy consumption is low.

Abstract: An X-ray examination apparatus includes an X-ray filter with a plurality of filter elements for locally attenuating the X-ray beam. The X-ray absorptivity of each filter element is controlled by the amount of X-ray absorbing liquid with which the filter element is filled. The filling of filter elements is controlled by a voltage. The X-ray absorbing liquid contains a suspension of very small X-ray absorbing particles.

Abstract: The invention relates to a controllable thermionic electron emitter for vacuum tubes, which comprises an emitter layer (3, 27) and a control layer (5) which is separated from the emitter layer by an insulating layer (4), with the insulating layer and the control layer being manufactured by a deposition process. Also when its dimensions are small, such an electron emitter can be dimensionally accurately manufactured. All functional elements of the controllable thermionic electron emitter, more particularly control layer(s) (5, 7, 22, 24), emitter layer (3, 27) and separating insulating layers (2, 4, 6, 21, 23, 25) are successively deposited on a substrate (1, 20) in the direction of growth, in such a manner that the layers adhere to each other via solid boundary layers. In operation and, in particular, when the temperature varies, the dimensional accuracy of the electron emitter is preserved within narrow limits, and said electron emitter has a long service life.

Abstract: A method of manufacturing a multilayer ceramic electronic component which comprises alternately conductive layers and dielectric layers, and in which successive, conductive layers are made alternately from two different electrode materials and extend up to the surfaces of all four side faces of the substrate, in which method, an end face of the stack of layers is immersed in an electrolytic solution and the least noble electrode material of the two electrode materials is electrochemically dissolved out, the resultant cavities are filled with a curable monomer, the noblest one of the two electrode materials is exposed by removing the polymeryzate formed, and a potential is applied to said electrode material, which is so high as to enable said noble electrode material at the other end face of the stack to be electrochemically dissolved out, the resultant cavities at the other end face are filled with a curable monomer, and outer electrodes are provided on opposite sides of the stack.

Abstract: In the manufacture of preforms for optical fibres, the materials of the core (.alpha.) and of the light-conducting cladding layer (.beta..sub.1) are previously deposited from the gaseous phase. Deposition time is here considerably reduced in that only the materials of the core (.alpha.) and a part of the light-conducting cladding layer (.beta..sub.1) are deposited from the gaseous phase and the remaining light-conducting cladding material (.beta..sub.2 +.beta..sub.3) is supplied as pre-formed tubes of cladding material.

Abstract: An optical fibre of the single-mode type in which light travels in one polarization mode is formed from a single-mode quadruple-clad fibre, in which the dimension of the light-transmitting part of the fibre in a first direction perpendicular to the axis of the fibre differs from the dimension of the light-transmitting part in a second direction perpendicular to the axis of the fibre and the first direction.

Abstract: A substrate (35) is coated by using starting materials which are supplied in the form of clusters (28). The clusters are disintegrated into their molecular or atomic constituents, and the constituents are deposited on the substrate in the form of compact layers (34). In this manner it is attained that the layers have a defined structure and do not exhibit inclusions in the form of foreign molecules.

Abstract: Electrically conductive multicomponent material is deposited on a tubular substrate (3) by means of a PCVD method. A plasma (9) is produced between an inner electrode (13) and an outer electrode, one of which is tubular and serves as a substrate. In order to obtain multicomponent material of the desired composition, the composition of the gas phase is changed as a function of time and/or place. In particular when metalorganic starting compounds are used, PCVD of many single layers together with an intermittent, for example, Ar/O.sub.2 plasma intermediate treatment yields an efficient removal of undesired carbon or fluorine from the deposited multicomponent material already during its manufacture.

Abstract: Method of and arrangement for manufacturing rotationally symmetrical porous solid bodies.A method of manufacturing rotationally symmetrical porous solid bodies, in which the starting material for the solid body in the form of a suspension consisting of the material for the solid body in solid form and a liquid dispersing agent, is introduced into a hollow mould whose geometry corresponds to that of the solid body to be formed, such that during the introduction of the suspension the hollow mould is rotated about its longitudinal axis, a certain quantity of solid of the suspension being deposited on the inner wall of the hollow mould, and excess residual suspension being removed, after which the green body thus formed is subjected to further process steps to manufacture the solid body, in which process suspension is introduced into the hollow mould in such doses that each time only thin solid layers having a thickness in the range from 10.sup.

Abstract: Layers of electrically conductive material are deposited in a standing microwave field. The deposition is done on an electrically conductive substrate in which a part of the surface forms a part of the inner wall of a microwave cavity resonator. As a result of this the microwave energy is used optimally. Measures are taken to keep the coupling place of the microwave ("window") free from an electrically conductive growth. The substrate is preferably moved periodically or aperiodically relative to the plasma and the remaining walls of the resonator.

Abstract: Optical fibres whose refractive index profiles show specific peripheral and/or radial and/or axial optical modulation structures are manufactured according to the PCVD method, in which such method parameters are varied which influence:(a) the uniformity of the material transport to the inner wall of the tube and/or the deposition yields of the glass over the tube circumference and/or(b) the axial position of the local deposition zone with respect to the reactor producing the plasma.

Abstract: The inside of a tube of an electrically insulating material is coated with a layer of electrically insulating material by reactive deposition of the coating material from a gas mixture which is passed through the tube. The tube is heated and the deposition is activated by a plasma produced by microwaves. The plasma reciprocates in the tube. Energy consumption is reduced by heating the tube to the reaction temperature at least partly by the energy supplied by the plasma to the tube wall. Thermal losses of the tube are reflected back to the tube wall by a heat reflecting element.

Abstract: For the reactive deposition of tubular bodies of electrically conductive material from a flowing gas phase on a tubular substrate, a glow discharge 11 is produced between an inner electrode 6 and an outer electrode 2, one of which is constructed so as to be tubular and serves as a substrate. It is ensured that the electrodes 2, 6 are not short-circuited by growing conductive surface layers so that the glow discharge 11 extinguishes. Furthermore, the electrically conductive coating on the electrode 6 which does not function as the substrate electrode is interrupted in an insulating manner to locally limit the glow discharge 11. For example, by a gas barrier the deposit of an electrically conducting material on the insulation can be avoided. The glow discharge 11 is reciprocated during the deposition process.

Abstract: Method and equipment for the manufacture of glass bodies wherein a porous green body is formed by extrusion from the starting material for the glass body in the form of a plastic mass and this green body is then purified and sintered, the plastic mass being transformed into a state of reduced viscosity by the application of mechanical forces utilizing the thixotropic effect and being extruded in this state.

Abstract: Optical waveguide circuits, such as signal splitters, can be produced by etching grooves in a transparent, glass substrate and by filling the grooves with glass having a higher refractive index than the material of the substrate. The grooves have a semicircular cross-section and the filling glass is produced by a low temperature plasma-activated chemical vapor deposition process. Two substrates can be placed on top of each other, with the surfaces in which the filled grooves have been provided in contact, to form an integrated optical circuit.

Abstract: The undulation of hot-moulded glass is avoided when the cooling of the glass edge layers in the first phase of the moulding operation is delayed and is accelerated after completed moulding. This is achieved by using a mould of a glassy carbon having a porous structure. Prior to the moulding, the pores are filled with a gas-forming liquid or a gas. The resulting gas film between the glass and the surface of the mould is removed ater completed moulding. The pores may subsequently be filled with a cooling agent.