Abstract: A substrate is made for silicon solar cells by heating a sheet of large-grained silicon steel at a temperature of at least about 1300.degree. C. in an atmosphere of hydrogen and tungsten hexafluoride (or hexachloride) at a partial pressure ratio of hydrogen to tungsten hexafluoride of about 3 to about 6 to deposit an epitaxial layer of tungsten on said sheet of silicon steel. Epitaxial silicon can then be deposited in a conventional manner on the layer of epitaxial tungsten.

Abstract: A process for implanting a precise quantity of radioactive metal on a metal substrate such as a cutting tool or other metal part subject to wear at the area or areas where the part is expected to wear during its operation. The presence of the radioactive spot can be sensed to determine the extent of wear during use. The radioactive metal is deposited from a wire formed of a core of the radioactive metal surrounded by a sheath of metal having a high thermal and electrical conductivity relative to the core. In operation, the wire contacts the metal surface under pressure and electric current is passed through the wire in order to (1) form a pit on the tool surface, (2) weld the radioactive metal in the pit and (3) evaporate a small portion of the conductive sheath adjacent the pit. A second current then is passed through the wire to break it near the bottom of the pit, leaving a small quantity of radioactive material welded to the bottom of the pit.

Abstract: There is disclosed herein a glass-to-metal seal construction especially adapted for use in the fabrication of devices of the compact arc discharge lamp or gas discharge laser type.

Abstract: A protective layer of tungsten or molybdenum is tightly adhered via an intermediate layer of pure nickel to a substratum of nickel-base alloy containing a carbide-former. The protected substratum is used in the structural components for a helium cooling circuit of a high temperature nuclear reactor. The protective layer is of a thickness of from 0.5 to 0.2 millimeters while the intermediate layer is of a thickness of 0.01 to 0.05 millimeters.

Abstract: A low-current contact structure formed on a contact member or substrate of various layers is described. A layer of refractory material is connected via a layer of easily diffusive metal with a layer of noble metal through diffusion annealing.