Abstract: A cooling structure (16) for use inside a ceramic cylindrical tube (11) of a metal vapor laser (10) to cool the plasma in the tube (11), the cooling structure (16) comprising a plurality of circular metal members (17, 31) and mounting members (18, 34) that position the metal members (17, 31) coaxially in the tube (11) to form an annular lasing volume, with the metal members (17, 31) being axially spaced from each other along the length of the tube (11) to prevent the metal members from shorting out the current flow through the plasma in the tube (11) and to provide spaces through which the heat from localized hot spots in the plasma may radiate to the other side of the tube (11).

Abstract: A landfill (10) having a leachate collection apparatus including a layer of geonet material (40) disposed above a liner (38) as its primary leachate flow path. Leachate flows along the geonet material to a collection trench (16) located along an edge (14) of a generally planar landfill area (12). The superior hydraulic conductivity of the geonet material (34) disposed above a liner (32) is provided below the primary drainage layer for additional ground water protection. A collection box 918) having both a leachate collection compartment (54) and a leakage collection compartment (56) is disposed in alignment with openings (80, 82) formed in the respective liner layers. The sealing surfaces (64,68) between the collection box and liners are all located on upper surfaces of the collection box.

Abstract: A compact high power magnetic compression apparatus and method for delivering high voltage pulses of short duration at a high repetition rate and high peak power output which does not require the use of environmentally unacceptable fluids such as chlorofluorocarbons either as a dielectric or as a coolant, and which discharges very little waste heat into the surrounding air. A first magnetic switch has cooling channels formed therethrough to facilitate the removal of excess heat. The first magnetic switch is mounted on a printed circuit board. A pulse transformer comprised of a plurality of discrete electrically insulated and magnetically coupled units is also mounted on said printed board and is electrically coupled to the first magnetic switch. The pulse transformer also has cooling means attached thereto for removing heat from the pulse transformer. A second magnetic switch also having cooling means for removing excess heat is electrically coupled to the pulse transformer.

Abstract: A segmented coaxial laser shell assembly having at least two water jacket sections, two pairs of interconnection half rings, a dialectric break ring, and a pair of threaded ring sections. Each water jacket section with an inner tubular section that defines an inner laser cavity with water paths adjacent to at least a portion of the exterior of the inner tubular section, and mating faces at the end of the water jacket section through which the inner laser cavity opens and which defines at least one water port therethrough in communication with the water jackets. The water paths also define in their external surface a circumferential notch set back from and in close proximity to the mating face. The dielectric break ring has selected thickness and is placed between, and in coaxial alignment with, the mating faces of two of the adjacent water jacket sections.

Abstract: A collapsible `bedspring` monopole antenna is configured to be effectively non-observable in its collapsed condition and, when deployed, remains sufficiently compact to ensure very low observability characteristics, while providing broadband coverage over a wide viewing aperture. The antenna is comprised of a conductor formed as a tapered helix. One end of the conductor is coupled to an antenna feed. The outer end of the helix is looped around on itself to form a circular loop. A plurality of substantially rectilinear `radials` are soldered to distributed locations around its circular loop, so as to extend outwardly and tangentially from the outer perimeter of the loop and provide `top hat` capacitive matching elements. To define the height of the deployed antenna and to electrically short out plural locations of the helix, a plurality of conductive straps are joined to respective spaced apart locations of the helix.

Abstract: In a time division multiple access satellite communications system having a master station and one or more remote stations, frequency offset through the translation oscillator in the satellite is corrected by transmitting a pilot frequency signal, reference to a high precision oscillator, through the satellite, so as to subject the pilot frequency signal to a frequency translation and monitoring the frequency translation of the pilot frequency signal as received at the master station subsequent to its transmission through the satellite. Signals to be transmitted over the satellite communications link from the master station to remote stations are subjected to a frequency translation that is effectively complementary to the monitored frequency translation.

Abstract: Method of formation of lenses at optical fiber ends to increase the coupling efficiency thereof. In a first embodiment, the end of the optical fiber is masked with a substance non-soluble in the etching reagent. The portion of the coating at the very end of the fiber is then removed and the fiber end immersed in an etching reagent. The etching reagent serves to dissolve the uncoated portion of the fiber. By controlling the amount of time that the fiber end is in the reagent, different lens shapes may be formed. In a second embodiment, the fiber end is dipped into a liquid epoxy compound whereby a portion of the epoxy is deposited onto the fiber end. The surface tension of the portion deposited thereon draws the liquid epoxy into the desired lens shape. The epoxy is then hardened to form a permanent lens structure on the fiber end.

Abstract: A low distortion modulated light source, including a light emitting diode and a compensating diode. These diodes are arranged in parallel for D.C. biasing, and in anti-series with respect to the A.C. signal path. Means are provided for varying the relative biasing of the two devices so as to thereby adjust the A.C. characteristics of the compensating diode to more accurately correspond to the A.C. characteristics of the light emitting diode.When properly biased, the inherently non-linear junction capacitance of the light emitting diode is compensated so as to substantially eliminate undesired harmonics and intermodulation products.