Abstract: A pair of planar electrodes spaced from one another by an electrolyte. The front electrode faces the air or vacuum environment and is transparent, and the second electrode is in thermal contact with a heat conducting surface and is reflective. By selectively modifying the voltage between the two electrodes, a partially reflective coating can be deposited on the back face of the front electrode or removed therefrom. With the coating removed, the emission of thermal radiation is minimized, and a major portion of the radiation from sources in the environment is reflected. With the coating present, emitted or reflected radiation interacting with the coating interferes destructively with the radiation emitted or reflected by the second electrode, maximizing thermal emission and absorbing a major portion of any incident radiation.

Abstract: The heat pipe has a condensing area at one end and an evaporating area at the other end. An ion drag pump is within the condensing area to receive dielectric refrigerant condensate in its inlet. There is a liquid carrying tube having one end connected to the pump outlet and having its other end terminating adjacent the evaporating area to discharge refrigerant condensate therein. The evaporating area has heat receiving flow paths into which the condensate is adapted to flow and be vaporized, there being a vapor flow path from the evaporating area through which the vaporized refrigerant returns to the condensing area.The method includes cooling one end of the heat pipe to liquefy refrigerant therein to form a condensate, flowing the condensate into an ion drag pump and applying a sufficiently high voltage across a cathode and anode of the pump to produce ions in the refrigerant condensate, the ions then being accelerated toward the anode so as to create fluid motion and pumping action through the pump inlet.

Abstract: Tapered seals are provided for sealing the ends of a flow-through module ch is mounted in parallel guide rails. Each seal is bonded to the end of a heat exchanger core and is a rectangular wedge having a thinner end at the bottom and a thicker end at the top. A complimentary tapered surface is provided in each slot of a plurality of slots in the parallel guide rails and, when an electronic module is inserted into the guide rails, a wedging action takes place to firmly position a module in the guide rails and seal the air passageway in the heat exchanger core to the guide rails.

Abstract: Protection of microwave antennas from incident irradiation from high power lasers is accomplished by placing a protective covering or radome over antenna elements to be protected. The radome is constructed such that it is substantially transparent to electromagnetic radiation in the microwave frequency range and at the same time substantially opaque to electromagnetic radiation in the laser frequency range. The radome is constructed of multilayers of a refractory ceramic material, such as boron nitride and beryllium oxide, spaced apart with the spaces evacuated. When the electromagnetic radiation from a high power laser strikes the radome of this invention, the opaqueness to the laser energy causes a conversion to heat energy which is then insulated from sensitive antenna elements by the evacuated spaces separating the refractory ceramic layers.