A mold suitable for casting therein molten metal or other molten materials wherein the mold includes a heat exchange surface, the mold includes means for providing a flow of coolant liquid to remove heat from the heat exchange surface by formation of nucleate vapor bubbles on the heat exchange surface, the liquid tending to include a viscous sublayer adjacent to the heat exchange surface, the improvement wherein the heat exchange surface includes at least one of: means for forming pressure gradients in the liquid having a component perpendicular to the heat exchange surface to facilitate removal of the nucleate bubbles; and means for breaking up the viscous sublayer to facilitate removal of the nucleate bubbles, and wherein the heat exchange surface comprises a series of concave curved surfaces and wherein septum members with corresponding curved surfaces, which may be split to permit positioning into close proximity to the heat exchange surface to provide desired coolant flow characteristics over the surfaces of the mold heat exchange surface, the septum members being bonded to axial structure elements that fasten to end members mounted on the mold whereby support is provided to the septum members and desired liquid flow patterns are obtained.

There is disclosed a novel high heat flux liquid cooled semi-conductor heat sink of modular construction suitable for semi-conductor chips such as IC's, hybrids, lasers, and power semi-conductors, said modular heat sink containing inserts with chip substrates made of metals, such as tungsten or molybdenum, said substrate including at least one surface suitable for bonding one or more semi-conductor chips in intimate thermal relationship thereto, and including a heat exchange surface on the interior surface thereof, said module providing means for enclosing said heat exchange surface in a liquid tight manner and including means for providing a flow of coolant liquid to remove heat from said heat exchange surface by formation of nucleate vapor bubbles on said heat exchange surface, the improvement wherein said heat sink module comprises individual heat sink inserts upon which semi-conductor chips are intimately bonded, said heat sink element being provided with means to electrically isolate each heat sink element from all other heat sink elements mounted on said heat sink module, said heat sink elements having their corresponding liquid cooled surface directly opposing said semi-conductor chip, the heat transfer characteristics of said liquid cooled surface being unobstructed by said electrically isolating means.

An oil-cooling system is provided for a multi-staged depressed collector of a linear beam device, such as an inductive output tube or klystron. The multi-staged depressed collector comprises a plurality of electrode stages adapted to have respective electric potentials applied thereto. The electrode stages are separated from one another by respective electrical insulators. The electrode stages are provided with a plurality of channels that extend axially along the outer surfaces of the electrodes. An inner sleeve is disposed in contact with the outer surface of the electrode stages and substantially encloses the plurality of channels. An outer sleeve encloses the inner sleeve with a space defined therebetween. The inner sleeve further includes an opening at an end thereof providing an oil communication path between the space between the inner and outer sleeves, and the plurality of axially extending channels. An oil source is coupled to one of the inner sleeve and the outer sleeve in order to provide a flow of oil therethrough. In an embodiment of the invention, the outer sleeve is comprised of steel, and the inner sleeve is comprised of TEFLON. The oil-cooling system provides cooling to the entire surface of the collector, including the electrode stages and the electrical insulators. The oil resists voltage breakdown, and permits a cooling structure that takes up less space than air or water-cooling systems.

A method for providing an approximately uniform temperature distribution on a cold plate that has at least one of a non-uniform temperature distribution on its heated surface and non-uniform wall thickness separating the heated surface from the generally opposing fluid cooled surface. Low thermal conductivity material is selectively deposited on the fluid cooled surface of the cold plate such that the resulting local thermal resistivity combined with the corresponding local heat flux results in an approximately constant temperature over the heated surface on the cold plate.

A liquid cooled melt spin chill casting apparatus suitable for melt spin chill casting of molten metals or other materials wherein a heat transfer rate capability greater than the heat load of the molten material is achieved. Structures produce multiple strands of material and strands of predetermined length. Additionally, the length of time the material is retained in contact with the casting wheel is controlled.