Abstract: A modular welding apparatus comprises a welding assembly having a welding head with an integral actuating assembly. A foot treadle initiates motion of the welding head. A conductive base member is spaced from the welding head. A welding power supply has one lead connected to the welding head and a second lead connected to the base member. An interchangeable welding module is disposed on the base member in electrical contact therewith. The welding module includes a conductive support plate and a locking cam for detachably attaching the support plate to the base member. Two movable, pre-aligned welding electrodes are disposed on the welding module. One of the welding electrodes is electrically connected to the base member and the other welding electrode is electrically connected to the welding head. At least one of the electrodes is in communication with the actuating assembly.

Abstract: A modular welding apparatus comprises a welding head assembly having a welding head with an integral actuating assembly. A foot treadle initiates motion of the welding head. A conductive base member is spaced from the welding head. A welding power supply has one lead connected to the welding head and a second lead connected to the base member. An interchangeable welding module is disposed on the base member in electrical contact therewith. The welding module includes a conductive support plate and a locking cam for detachably attaching the support plate to the base member. A welding mandrel comprising one welding electrode is in contact with the support plate. An insulating member is attached to the support plate and an articulated welding electrode assembly is attached to the insulating member.

Abstract: A planar mesh structure that facilitates forming into a non-planar mesh structure comprises a peripheral support ring lying in a plane with a plurality of first members and a plurality of second members lying in the plane. The first members comprise substantially concentric, spaced-apart mesh rings of progressively decreasing diameter disposed within the peripheral support ring. The plurality of second members extend generally inwardly from the peripheral support ring and terminate at the innermost of the first members. The second members intersect the first members disposed between the peripheral support ring and the innermost first member to form, with the intersected first members, a plurality of apertures. In one embodiment, the second members are generally arcuately shaped and lie in a first plane with the support ring and the first members.

Abstract: A photomultiplier tube comprises an evacuated envelope having a generally cylindrical sidewall with a faceplate closing one end of the envelope. A conductive coating is disposed on a portion of the sidewall adjacent to the faceplate. A photocathode is formed on the faceplate and on a portion of the conductive coating. An electron multiplier assembly including a plurality of electrodes is spaced from the photocathode. A plurality of leads extend from the electrodes to a plurality of terminals in a base attached to the tube. A resilient electrical contact member is connected to a terminal in the base for applying a potential to the photocathode. The electrical contact member has a pair of support tabs at the opposite ends of the member. The tabs are affixed to the multiplier assembly so that the contact member assumes a substantially arcuate shape which contacts and conforms to a large area of the conductive coating on the sidewall of the envelope.

Abstract: A photomultiplier tube comprises an electron multiplier assembly including a pair of oppositely-disposed insulative support spacers. A plurality of elements including an ultimate dynode and an anode are affixed to the support spacers. The ultimate dynode comprises a relatively inflexible multilateral hollow member having two plane-face surfaces lying at an acute angle to one another and terminating at a lower transverse edge. The ultimate dynode includes dynode mounting tabs extending from opposing ends thereof for affixing the ultimate dynode to the support spacers. The anode includes a substantially flat electron permeable mesh portion spaced from one of the plane-face surfaces of the ultimate dynode. Anode mounting tabs extend from opposing ends thereof for affixing the anode to the support spacers. Electrical leakage isolation slots are formed in the support spacers to increase the electrical leakage path length across the support spacers between the ultimate dynode and the anode.

Abstract: A film of photoemissive material, such as antimony, is vaporized from a platinum-antimony source onto a substrate in an enclosure. The source is preferably a plurality of beads formed by attaching substantially spherical particles of platinum-antimony (50--50 by atomic volume) to a platinum-clad molybdenum wire. The spherical particles are accurately sized so that each bead comprises substantially the same amount of antimony. The beads are symmetrically arranged about the substrate so that upon evaporation a substantially uniform film of photoemissive material is deposited on the substrate.

Abstract: An alkali metal dispenser in an electron tube for vapor depositing alkali metals on photoemissive surface within the tube envelope comprises a non-welded-tubular housing having walls formed by spirally rolling upon itself a thin sheet of tantalum so that the walls spirally overlap, preferably twice. The "double wrapped" dispenser prevents uncontrollable escape of alkali particles contained within the interior of the tubular housing and provides a substantially uniform orifice for repeatable release of alkali vapors.