Abstract: An improved material for an ultrasonic transducer assembly having improved noise suppression characteristics comprising an ultrasonic transducer having a plurality of surfaces, a housing for receiving said transducer whereby one surface of said transducer is free to transmit and receive ultrasonic waves, and a material positioned about said transducer and between said transducer and the environment or housing for attenuating ultrasonic energy, said material comprising a heavily loaded resin based on an unfilled low viscosity potting gel and a filler selected from the group consisting of heavy oxides, metal powders, and density lowering fillers. In specific embodiments lead oxide, tungsten powder, and glass microspheres have been used as the filler in a silicone or flexible epoxy.

Abstract: An electromagnetic projectile launching system utilizes two cylindrical rail configurations. In one configuration, multiple conductive armatures are electromagnetically accelerated along rails which are located on the inner surface of a cylindrical barrel. The second configuration utilizes armatures located between concentric cylindrical rails. Rifling provides for spin stabilization of the projectile.

Abstract: A torque structure particularly suitable for utilization in a power reactor of the Tokamak-type, and operable therein for purposes of providing support for the toroidal field (TF) coils that comprise one of the major operating components of such a Tokamak power reactor. The subject torque structure takes the form of a frame structure that is operable to enable torque loads acting on the TF coils to be equilibrated as close to the area of force application as feasible. The aforesaid torque structure includes an intercoil structure composed of spacer wedges that are interposed between each adjacent pair of TF coils. The spacer wedges, in turn, consist of bearing plates positioned between the TF coils so as to be in contacting relation therewith and a number of cross plates that are cooperatively associated with the bearing plates so as to form therewith a rigid assembly. The intercoil structure is affixed to a segmented, membrane shell that surrounds, encloses and supports the TF coil frames.

Abstract: A method and means for accelerating charged particle beams having very high current densities to relativistic energies, as, for example, embodied in a betatron capable of carrying a current of many tens of kiloamperes at energies up to at least 300 Mev. The basic principle underlying the present invention is the containment of a beam of charged particles, more particularly a beam of electrons, by a magnetic field directed along the beam. As the strength of the magnetic field is increased as a function of time the beam of electrons becomes compressed in the direction transverse to the beam into a region of high charge density. The electrons may then be accelerated along the direction of the magnetic field to form an ultra-relativistic beam. At such high energies the beam tends to be stable and the containing magnetic field is no longer necessary. The magnetic field may therefore be permitted to decay.

Abstract: A nuclear fuel element for use in the core of a nuclear reactor is disclosed and has a composite cladding having a substrate and a metal barrier metallurgically bonded on the inside surface of the substrate so that the metal barrier forms a shield between the substrate and the nuclear fuel material held within the cladding. The metal barrier forms about 1 to about 30 percent of the thickness of the cladding and is comprised of a low neutron absorption metal of substantially pure zirconium. The metal barrier serves as a preferential reaction site for gaseous impurities and fission products and protects the substrate from contact and reaction with such impurities and fission products. The substrate of the composite cladding is selected from conventional cladding materials and preferably is a zirconium alloy. Methods of manufacturing the composite cladding are also disclosed.

Abstract: Disclosed is a method and apparatus for enhancing the brightness of both continuous and pulsed positron beams. By subjecting positrons to non-conservative forces in an interaction region, typically by means of a positron moderator such as a single crystal Cu(111)+S moderator, it is possible to circumvent the limitation, expressed in Liouville's theorem, of the optimally achievable brightness of a beam. The inventive method can be applied in successive stages involving accelerating and focusing a moderated positron beam, and moderating the energetic positrons to thermal energies, resulting typically in an increase in brightness by a factor of about 100 per stage, with an attendant reduction of flux by about factors of ten or less.

Abstract: The invention relates more particularly to a pressurized water nuclear reactor in which the heat exchange between the primary and secondary circuits takes place by means of steam generators.A reserve tank is placed in the secondary circuit parallel to the steam generator and inside or outside the latter. It is pressurized directly by the secondary fluid in the gaseous phase leaving the generator, so as to form a reserve increasing the inertia of the generator in the case of closing the steam and supply valves without significantly increasing it in the case of a fracture of the steam piping.Application to pressurized water nuclear reactors.

Abstract: A mounting for use in conjunction with a laser in an installation where the structure may be subjected to destructive shock. The structure includes an external rigid shell to contain the laser head and power supply panel. The shell encloses impact absorbing shock mounts or plates which serve to retain shock reduction cushions which surround the laser head and support it within the shell returning it to its appropriate position following shock. A shock absorbing bracket is provided to mount the entire unit in position.

Abstract: Two different cavitation fusion reactors (CFR's) are disclosed. Each comprises a chamber containing a liquid (host) metal such as lithium or an alloy thereof. Acoustical horns in the chamber walls operate to vary the ambient pressure in the liquid metal, creating therein small bubbles which are caused to grow to maximum sizes and then collapse violently in two steps. In the first stage the bubble contents remain at the temperature of the host liquid, but in the second stage the increasing speed of collapse causes an adiabatic compression of the bubble contents, and of the thin shell of liquid surrounding the bubble. Application of a positive pressure on the bubble accelerates this adiabatic stage, and causes the bubble to contract to smaller radius, thus increasing maximum temperatures and pressures reached within the bubble. At or near its minimum radius the bubble generates a very intense shock wave, creating high pressures and temperatures in the host liquid.

Abstract: Methods and apparatus for plasma generation, confinement and control such as Tokamak plasma systems are described having a two layer field shaping coil system comprising an inner coil layer close to the plasma and an outer coil layer to minimize the current in the inner coil layer.

Abstract: A cooling system for a gas-cooled nuclear reactor is disclosed which includes at least one primary cooling loop adapted to pass coolant gas from the reactor core and an associated steam generator through a duct system having a main circulator therein, and at least one auxiliary cooling loop having communication with the reactor core and adapted to selectively pass coolant gas through an auxiliary heat exchanger and circulator. The main and auxiliary circulators are installed in a common vertical cavity in the reactor vessel, and a common return duct communicates with the reactor core and intersects the common cavity at a junction at which is located a flow diverter valve operative to effect coolant flow through either the primary or auxiliary cooling loops.

Abstract: Contactless transmission of information about temperatures within a fuel assembly of a nuclear reactor by means of a thermoelement situated in the fuel assembly, the thermoelement generating a magnetic field the intensity of which is proportional to the temperature within the fuel assembly. A harmonic magnetic sensing element disposed outside the fuel assembly for registering the value of intensity of this magnetic field is employed, the sensing element being connected to an arrangement for the evaluation of such. The fuel assembly is provided with a sheath or housing which permits the passage of the magnetic field therethrough.

Abstract: Fuel can failures are located by measuring the age of a faulty fuel element. The method consists in determining the ratio between two fission products constituted by two stable gaseous isotopes of xenon having different kinetics of formation of available gas as a function of the burn-up of the fuel elements.

Abstract: Defects in nuclear fuel elements are ascertained and located within an assembled fuel assembly by ultrasonic means. In a typical embodiment of the invention, an ultrasonic search unit is positioned within the fuel assembly opposite the lower plenum of the fuel element to be tested. An ultrasonic pulse is radially projected into the element. Defective fuel elements are ascertained by ultrasonic reflection measurements.

Abstract: A control rod having a spring device on its lower end for eliminating oscillatory contact of the rod against its adjacent guide tube wall. The base of the device is connected to the lower tip of the rod. A plurality of elongated extensions are cantilevered downward from the base. Each extension has a shoulder for contacting the guide tube, and the plurality of shoulders as a group has a transverse dimension that is preset to be larger than the inner diameter of the guide tube such that an interference fit is obtained when the control rod is inserted in the tube. The elongated extensions form an open-ended, substantially hollow member through which most of the liquid coolant flows, and the spaces between adjacent extensions allow the flow to bypass the shoulders without experiencing a significant pressure drop.

Abstract: In a method and a system for inspection of the inside of a nuclear reactor vessel in which an inspection device for inspecting a defect in a nuclear reactor vessel is so moved by a drive/control device as to permit inspection of a part to be inspected in the reactor vessel, and the presence or absence of defect in the reactor vessel is judged based upon information from the inspection device in the course of the above-mentioned movement of the inspection device; the movement of the inspection device is pursued and monitored by monitor means, and the movement of the inspection device is suppressed when an abnormality in the movement of the inspection device is judged based upon information from the monitor means, to avoid the abnormal movement.

Abstract: A system for determining whether a self-sustaining neutron chain reaction (i.e., criticality) may occur as each successive nuclear fuel element is added to a liquid-filled tank. This is accomplished by determining whether a multiplication factor, k, approaches unity after each element is added to the tank in accordance with the equation:CR=(.alpha.S)/(1-k)where:S is the emission rate of the neutron source;.alpha. is a term that reflects the detector sensitivity as well as the attenuation of the neutron between source and detector and various geometric considerations in the tank;CR is the counting rate from a neutron detector; andk is a multiplication factor of the assembly at any given time for any given element configuration.

Abstract: A piston is moved by a laser incited fusion reaction such as deuterium-tritium (D-T) to thereby produce an expandable fusion chamber. When a gaseous substance such as CO.sub.2 is presented in the presence of the fusion reaction, it is dissociated into CO and O.sub.2 component mixture and the expansion of the chamber rapidly cools the mixture and quenches the back reaction thereby producing a greater CO yield. Also the piston produces peripheral power from the fusion reaction in the form of mechanical energy.

Abstract: A system for discriminating between hard object impact detected by a transducer and background noise or electrical noise spikes, which uses the detection of a series of cross-over points during a plurality of time intervals as an indication of a true impact signal.

Abstract: The fuel-air mixture preparation system of an internal combustion engine is engaged by signals from a plurality of oxygen sensors located in the exhaust system of the engine. More than one sensor is provided to improve the quality of the output signals in unfavorable engine operation. The individual sensors are provided with comparators which make a comparison between the sensor output and a set-point signal. The output signals from the comparators are fed to a logically controlled coupling circuit which presents them in cyclic alternation to an integrating control circuit which provides a control signal to the final control element in the fuel mixture preparation system for changing the fuel-air ratio. The coupling circuit may also provide a signal based on the logical states of the individual sensor signals.