Abstract: A method for chemical decontamination of the surface of a metal component of a nuclear reactor plant includes treating the surface of the metal component in a single-step method with an aqueous solution that is free of carbonic acid oxalic acid and contains a different carbonic acid.

Abstract: Apparatus for the preparation of a semiconductor compound having one component with a substantially higher vapor pressure than the other using a closed horizontal ampule in a pressure vessel with the two ends of the ampule located in respective heating ovens in which the ampule is self supporting without a support tube in the zone between the heating ovens thereby permitting this zone, which is highly heated by means of an inductive heating apparatus or the like, to be cooled directly by means of a cooling gas circulating in the pressure vessel and in which the coupling of the heating means to a graphite boat or the like inside the ampule is improved.

Abstract: An apparatus for producing compact polycrystalline ingots of materials such as InP, GaP and GaAs having a defined geometric form is provided comprising a reaction boat having a plurality of melting pots formed therein, said melting pots having the shape of a single crystal melting crucible and at least one connecting canal communicating with said melting pots.

Abstract: An apparatus for preparing a semiconductor compound, having one compound with a substantially higher vapor pressure than the other using a closed horizontal tube disposed in a pressure vessel. The two ends of the tube are located in respective heating ovens having their ends facing away from the tube closed. The heating ovens and tube are disposed within a pressure vessel with the heating ovens having an outside diameter which is considerably smaller than the inside diameter of the pressure vessel and with the total length of the heating ovens arranged one behind the other in the axial direction of the tube substantially smaller than the length of the pressure vessel. In addition, a portion of the tube located between the ovens has associated therewith a separate cooling device.

Abstract: In apparatus for the preparation of a semiconductor compound such as gallium phosphide using the Bridgman method in a horizontal system equipped with a heating device and disposed in a pressure vessel, the reaction tube is mounted in a stationary fashion in a reaction boat and the heating device supported so that it is moveable in the direction of the horizontal axis of the system to permit synthesis of the semiconductor compound along with zone melting and drawing of single crystals. A light guide having its free end arranged below the reaction tube is mounted to the heating device for movement therewith and is used to measure the temperature at the reaction boat.

Abstract: A process for the production of compact polycrystalline III A - V B compounds such as GaP through direct synthesis from the components in a closed horizontal system, in which at least one of the components has a substantially higher partial vapor pressure over the molten compound being produced than do the other components. In carrying out the process, the components which are more difficult to vaporize are heated in a narrow reaction zone to a temperature in the range of 100.degree. to 500.degree. C below the congruent melting temperature of the compound being produced while the pressure of the easily vaporized components is adjusted so that it amounts to between 0.14 and 0.33 times the decomposition vapor pressure of the compound being produced and thus to 50 to 120 times the decomposition vapor pressure of the solution of the compound being produced in the components which are difficult to vaporize at the reaction temperature.

Abstract: In an apparatus for the preparation of compounds in which one of the components is a highly volatile reactive component, in particular when preparing gallium phosphide, under pressure in an ampoule located in a pressure vessel, between 0.5 and 25% by volume and preferably 1.5 to 3% by volume of a gas capable of reacting with the highly volatile component, such as oxygen, air or carbon dioxide, is mixed in the pressure vessel to the gas which is used for pressurizing and as a cooling medium and the pressure in the pressure vessel is matched to the internal pressure of the ampoule in which the reaction is taking place.

Abstract: Apparatus for measuring the temperature of a granular semiconductor material of the type which is evaporated when manufacturing a semiconductor such as gallium phosphide within an ampoule or reaction tube, in which a temperature sensor is installed in a measuring tube having a closed end extending into the ampoule and the semiconductor material therein and an opened end which is sealed into a suitable opening in the end of the ampoule with the electrical leads for the temperature sensor being brought out from the measuring tube through the opening in the ampoule.