Abstract: An apparatus and method by which a high-power laser beam and a high-energy article beam may enter or exit a region, typically filled with gas, to or from another region, typically under vacuum. The two beams are spaced about 3-4 mm apart center-to-center at the entry/exit point and no gas is permitted to leak into the vacuum region. A disc of material capable of resisting high radiation fluxes without forming color centers is sealed into a metallic holding block. Prior to sealing of the disc, a hole approximately 0.16 cm is drilled into the disc while the disc is tilted at or above Brewster's angle forming an elliptical hole. A thin film, approximately 6000 .ANG., indium metallization is sputtered in a circular pattern about the hole and around the edges of a beryllium disc. An indium disc is then sandwiched between the disc with the hole and the beryllium disc touching the indium metallization on each piece.

Abstract: An H-plane sectoral horn antenna is loaded with low-loss dielectric inserts n alternative embodiments so as to reduce beamwidth, increase axial gain and to achieve non-mechanical beam scanning. In one embodiment, the antenna is transversely loaded with a multi-layer dielectric array containing an air gap of critical thickness between four dielectric strips. In another embodiment, the antenna is longitudinally and symmetrically loaded with wedge-shaped dielectric strips separated by a critical air gap between the dielectric and antenna walls.

Abstract: A net recovery system for recovering torpedoes or the like from the surface f the water. The net recovery system consists of a net shaped into the configuration of the surface of a cone having a closed apex and an open circular base. A rigid hoop is attached to the open circular base. A main lift line has one end connected to a firing mechanism, such as a helicopter, and the other end connected to a releasable hook. A releasable lift line is connected at one end to the releasable hook and the other end connected to the apex of the net. A hoop lift line has one end connected to the main lift line above the releasable hook and the other end connected to the hoop. A net lift line has one end connected to the main lift line above the releasable hook and the other end connected to the apex of the net. The net lift line is substantially longer than the hoop lift line and the hoop lift line is substantially longer than the releasable lift line.

Abstract: In a gas turbine engine of the type wherein the fuel is injected through a pray injection nozzle into a combustion chamber, the improvement is a method and apparatus for modifying the characteristics of the fuel spray from the fuel injection nozzle so that fuels of higher aromatic content can be efficiently used in the engine. An electrode is disposed within the combustion chamber to provide a high strength electrostatic field in the vicinity of the injection nozzle so that the fuel spray from the nozzle becomes charged as it leaves the nozzle. The strength of the electric field is adjusted to provide a spray characteristic which produces optimum engine performance as determined by measuring an operating parameter of the engine such as the temperature of the gases exiting from the combustion chamber.

Abstract: A method and apparatus for constructing a continuous wave (CW) free elect laser (FEL) system capable of providing tunable high power laser radiation at short wavelengths using low-energy recirculating DC electron beams. This method replaces the static periodic magnetic field used in conventional FEL systems with an equivalently intense and continuous electromagnetic pump field having spatial periodicity less than 1 cm. The pump field is generated by a low-energy recirculated DC electron beam interacting with a transverse static periodic magnetic field.

Abstract: A solid state delay device for delaying digital data for short periods of me. Serial digital data is converted into parallel data and input to a number of parallel memory paths. The data is shifted through the memory paths by a clock synchronized with the data. The output of the memory path is reconverted to the original serial digital data delayed by the amount of time required to shift through the memory paths.

Abstract: A method for investigating the quality of dielectrically isolated thin film emiconductor layers in inversion-mode MOS devices having dual-gate control capabilities which allow two channels to be created in the semiconductor film. With one channel conducting and a drain voltage providing operation in the saturation region, a step voltage is applied to the gate associated with the second channel which has a transient effect on the current in the first channel. This transient may be analyzed to measure the generation lifetime and other parameters in the body of the device.

Abstract: An apparatus and method is described for greatly enhancing the power output f a free electron laser. To enhance the electron kinetic energy that is converted to laser radiation, the wave amplification resonance condition is continuously changed along the length of the laser interaction region. The changing resonance condition is achieved by use of a static magnetic field transverse to the injected electron beam, the magnetic field having a longitudinal magnetic field gradient.

Abstract: Apparatus for confining a leakage of polychlorinated byphenyl (PCB) from an utdoor electrical substation while permitting rain water to be discharged into the outside environment when no PCB is present. The electrical equipment is disposed on a walled pad having sufficient containment volume to hold the maximum PCB leakage. The outlet from the containment volume is through a water/PCB separator float valve which is disposed vertically in a catch basin. The valve has a tubular body having a flow-through section with apertures which communicate with the catch basin and a converging section of circular cross-section above the flow-through section. A spherical float having a specific gravity between that of water and PCB is confined in the tubular body.

Abstract: A method for optimizing the design of finite noise barriers by using an extension of the Biot-Tolstoy rigorous closed form impulse solution for diffraction of an acoustic pressure pulse by an infinite rigid wedge. An initial finite barrier is defined and then a calculation made of the impulse signal transmitted on one side of the barrier and received on the other side by adapting the Biot-Tolstoy solution to a digital computer. The integrals of the acoustic pressure impulse are calculated for each source/receiver path for each segment of the barrier. The integrals are then compared and the segments are adjusted and new calculations made until all integral contributions are equal. The integrals are then digitally Fourier transformed to determine attenuation at the desired frequencies. After comparison with the desired attenuation, all segments are proportionately adjusted and the entire computational process reiterated until the optimal attenuation is achieved.

Abstract: To achieve rapid mixing between a jet flow and its surrounding medium a v is mounted in the jet downstream of the jet nozzle exit. The vane is oscillated in either pitch or plunge by an appropriate excitation mechanism at a constant frequency. The amplitude of oscillation is typically only a few degrees. The oscillation frequency may be varied to control the entrainment rate.

Abstract: A gas generator outlet manufactured of different metals, each possessing ferent thermal capability, welded together with a tapered internal insulation system. The generator outlet is designed to contain a high-pressure gas having a flame temperature of 3000.degree. F. The external surface of the gas generator outlet remains at or below 600.degree. F. while the outlet interfaces with a metal manifold having a temperature of approximately 3000.degree. F.

Abstract: A method of separating and ejecting a re-entry body from a booster rocket thout tip-off by igniting a pair of diametrically opposed rockets attached to the base of the re-entry body which provide thrust at an angle, and then firing a plurality of pyrotechnically operated separation nut assemblies, with the attachment bolts being captured in bolt catcher assemblies, to separate the re-entry body from the booster rocket, the pair of rockets providing separation velocity and spin to the re-entry body.

Abstract: A method for sealing ports, ducts and the like using a fully consumable mrial as the sealing medium and utilizing the consumable capability to provide remote removal of the seal without damage to the sealed areas and with no remaining obstruction in the port, duct or the like. The fully consumable seal may be configured to the geometry of the aperture to be sealed and has thickness determined by pressure difference across the seal and time required to remove the seal.

Abstract: Passive apparatus for absorbing the kinetic energy of a collision to prot an underwater structure from damage in a collision which includes a ring suspended by a ring support system so that the ring is positioned between the structure and the expected path of potentially impacting objects. The ring support system includes eight rigid rods which have one end coupled to one of four symmetrically disposed supporting pylons by spherical sleeve bushings and their other end coupled by spherical rod ends to one of four standoff members that are fixed to the top surface of the ring at equal intervals around its circumference. A shock absorber is coupled between each supporting pylon and the ring midway between standoff members by spherical rod ends. The dimensions of the rigid rods and their attachment points to the supporting pylon and the ring are chosen so that the ring may pivot on the rods against the resistance of the shock absorbers in response to an impact, but cannot strike the enclosed object.

Abstract: A frequency selective limiter comprising a plurality of LC series-resonant filters having resonant frequencies uniformly spaced over the passband. Each filter is formed of two identical LC series-resonant sections with a diode limiter coupled between the two sections. The filters are coupled in parallel between the limiter input and the load to form two groups having alternate resonant frequencies with signals passing through one group being shifted in phase by 180.degree. relative to signals passing through the other group.

Abstract: In a system for isotope enrichment, a method and apparatus for separating atoms of one isotope type from an environment containing plural isotope types. Tunable lasers or laser systems are used to selectively pump atoms of the desired isotope to a metastable excited state several eV above the isotope atom ground state. A reduced ionization energy is then supplied to atoms of the metastable isotopes taking advantage of the longer lifetimes achieved. The resulting plasma created by ionizing atoms of the isotope in the metastable state is subjected to electromagnetic fields to separate atoms of the desired isotope.

Abstract: A method for removing residual oxygen from a growth solution prior to liq phase epitaxial crystal growth comprising the steps of disposing the materials in a containment vessel of a solid oxide electrolyte material under a protective atmosphere, heating the materials to form a liquid charge in the containment vessel, placing an electrode of an inert conducting solid in physical contact with the liquid charge, and applying a DC electric potential between the electrode and the containment vessel, the electrical contact to the containment vessel being made through a porous metallic coating of an inert metal on the outside surface of the containment vessel in the region where the liquid charge is contiguous to the inside surface of the containment vessel, the porous coating being relatively positive and the electrode being relatively negative.

Abstract: A method for steering solid propellant ballistic vehicles during powered flight which eliminates the requirement for cutoff control by allowing simultaneous fuel depletion and velocity-to-be-gained, V.sub.G, nulling. The vehicle booster is steered along a velocity trajectory of length equal to the remaining velocity capability, V.sub.CAP, which results in a fuel-inefficient trajectory. The trajectory is divided basically into three phases--an exit phase, a fuel-depletion guidance (FDG) phase and a short phase of constant attitude thrusting just prior to final stage burnout. For the exit phase the launch azimuth and the pitch-over magnitude can be varied from their usual fuel-efficient values. During fuel-depletion guidance the additional degree of freedom is the angle, .theta., between V.sub.G and the desired thrust direction, U.sub.S, where: ##EQU1## a.sub.T being the sensed acceleration vector.

Abstract: A loss-of-phase-lock indicator circuit is described which detects an out-limit voltage, whether steady or transitory. A pair of comparators, one for the high limit and the other for the low limit, are inserted in series between the tuning voltage and the sweep feedback amplifier, and are dc-coupled to the peak detector in the failure circuit. Additionally, a "dither" voltage is added in series with the phase detector, which ac voltage is large enough to swing the tuning voltage between limits at the loop amplifier output, but small enough to produce little effect on the output during phase lock.