Abstract: An object of the present invention is to efficiently improve uniformity of energy lines to be irradiated.

Abstract: Respective pulsed power supplies for plasma opening switches each produce a first current and a second current during a power pulse and a difference between the first current and the second current during a terminal portion of the power pulse. The pulsed power supplies are initiated or adjusted in response to measured opening times of the plasma opening switches in order to minimize or eliminate a need for command triggered opening of the plasma opening switches. Command triggered opening may occur in real time for a shot as needed in response to asymmetry of opening times of the plasma opening switches in the array during the shot.

Abstract: A pulsed power system has an inductive energy storage circuit (42) including a current source (43) and a plasma opening switch (44). The plasma opening switch has a transmission line (51, 52) coupling the current source to a load (41). The plasma opening switch changes from a closed state to an open state when a plasma discharge (45) in the plasma opening switch is driven by magnetic force from a first region along the transmission line to a second region towards the load. Electrical conductors (47, 48) are arranged for providing a stabilizing magnetic field configuration in the first region to magnetically latch the plasma discharge in the first region during charging of the inductive energy storage circuit, and current flowing along the transmission line from the current source to the load tends to disrupt the stabilizing magnetic field configuration and unlatch the plasma discharge from the first region and drive the plasma discharge toward the second region.

Abstract: A method and apparatus for the steady-state measurement of poloidal magnetic field near a tokamak plasma, where the tokamak is configured with respect to a cylindrical coordinate system having z, phi (toroidal), and r axes. The method is based on combining the two magnetic field principles of induction and torque. The apparatus includes a rotor assembly having a pair of inductive magnetic field pickup coils which are concentrically mounted, orthogonally oriented in the r and z directions, and coupled to remotely located electronics which include electronic integrators for determining magnetic field changes. The rotor assembly includes an axle oriented in the toroidal direction, with the axle mounted on pivot support brackets which in turn are mounted on a baseplate. First and second springs are located between the baseplate and the rotor assembly restricting rotation of the rotor assembly about its axle, the second spring providing a constant tensile preload in the first spring.

Abstract: This instrument can measure parameters of a plasma accurately and easily even though the plasma is exited by a high-frequency. The instrument for measuring parameters of a plasma generated in a vacuum chamber by high-frequency discharge at a given frequency comprises a wire (106) for electrically connecting a first electrode (101) arranged in a space where a plasma is produced and a terminal (110) arranged outside the vacuum chamber for taking out signals, and a first insulator (105) so arranged as to cover at least a part of the surface of the wire therewith. The absolute value of the impedance at the given frequency between the first electrode and the ground when looking into the terminal side from the first electrode is five times or more the absolute value of the impedance at the given frequency between the first electrode and the plasma in a state where no direct current flows through the first electrode.

Abstract: Invention comprises an instrument in which momentum flux onto a biasable target plate is transferred via a suspended quartz tube onto a sensitive force transducer--a capacitance-type pressure gauge. The transducer is protected from thermal damage, arcing and sputtering, and materials used in the target and pendulum are electrically insulating, rigid even at elevated temperatures, and have low thermal conductivity. The instrument enables measurement of small forces (10.sup.-5 to 10.sup.3 N) accompanied by high heat fluxes which are transmitted by energetic particles with 10's of eV of kinetic energy in a intense magnetic field and pulsed plasma environment.

Abstract: A fusion power generating device is disclosed having a relatively small and inexpensive core region which may be contained within an energy absorbing blanket region. The fusion power core region contains apparatus of the toroidal type for confining a high density plasma. The fusion power core is removable from the blanket region and may be disposed and/or recycled for subsequent use within the same blanket region. Thermonuclear ignition of the plasma is obtained by feeding neutral fusible gas into the plasma in a controlled manner such that charged particle heating produced by the fusion reaction is utilized to boot-strap the device to a region of high temperatures and high densitities wherein charged particle heating is sufficient to overcome radiation and thermal conductivity losses. The high density plasma produces a large radiation and particle flux on the first wall of the plasma core region thereby necessitating replacement of the core from the blanket region from time to time.

Abstract: A method including externally imposing an impulsive momentum-space flux to perturb hot tokamak electrons thereby producing a transient synchrotron radiation signal, in frequency-time space, and the inference, using very fast algorithms, of plasma parameters including the effective ion charge state Z.sub.eff, the direction of the magnetic field, and the position and width in velocity space of the impulsive momentum-space flux, and, in particular, the dc toroidal electric field.

Abstract: This invention relates to a power source for a nuclear fusion reactor for flowing a current to a load coil (e.g., a toroidal coil) provided in the nuclear fusion reactor such as a reversed field pinch apparatus comprising a bias power supply for supplying a current of a first direction to the load coil, and a reversed magnetic field power supply for supplying a current of a second direction reverse to the first direction to the load coil and having a circuit for holding the reverse current for a predetermined period of time, said bias power supply including a series circuit of a capacitor, a unidirectional element having a switching function and an inductor and connected in parallel with the load coil, thereby removing a clover element from the bias power supply.More particularly, according to this invention, when a current is flowed from the reversed magnetic power supply to the load coil, a current from the reversed magnetic power supply to the inductor in the bias power supply is stopped.

Abstract: A fusion power generating device is disclosed having a relatively small and inexpensive core region which may be contained within an energy absorbing blanket region. The fusion power core region contains apparatus of the toroidal type for confining a high density plasma. The fusion power core is removable from the blanket region and may be disposed and/or recycled for subsequent use within the same blanket region. Thermonuclear ignition of the plasma is obtained by feeding neutral fusible gas into the plasma in a controlled manner such that charged particle heating produced by the fusion reaction is utilized to bootstrap the device to a region of high temperatures and high densities wherein charged particle heating is sufficient to overcome radiation and thermal conductivity losses. The high density plasma produces a large radiation and particle flux on the first wall of the plasma core region thereby necessitating replacement of the core from the blanket region from time to time.

Abstract: A double swing power unit for use in a plasma nuclear fusion experimental system comprising a bias bank, a bias switch provided by a semiconductor switch element having a rectifying function, a decoupling inductor, and a load coil connected in series, a series connection of a reverse switch and a reverse bank and a series connection of a hold switch and a hold bank, both thereof being connected in parallel with the load coil, and a control switch connected in parallel with the bias switch.

Abstract: An experimental nuclear fusion reactor comprising a coaxial plasma gun which has an outer electrode and an inner electrode arranged coaxially with each other, a metallic container which generates an annular plasma round a center conductor and which holds a poroidal magnetic flux, an inlet which introduces a plasma from the coaxial plasma gun into the container, and conductor members which electrically connect the center conductor, either of the outer and inner electrodes, the inlet and the container in succession so as to form a closed circuit, wherein current to flow through the closed circuit is controlled to hold a toroidal magnetic flux of the annular plasma.

Abstract: A fusion device provides for the reaction of atomic nuclei, preferably deuterons and tritons, to generate reaction products with kinetic energies convertible to useful energy. First and second sources of first and second positive ions provide such ions at temperatures in a range where the ions have a substantially optimum cross section for mutual reaction. The respective ions are accelerated to substantially the same mean velocity and formed into respective beams. The beams are neutralized and directed into a portion of a reaction chamber substantially orthogonally of a substantially constant unidirectional magnetic field as first and second polarized beams of respective first and second positive hot ions. The polarization of the first and second polarized beams is drained, preferably by a plasma created in the portion of the reaction chamber, to separate the neutralizing electrons from the respective first and second positive hot ions.

Abstract: A plasma confinement system comprising a toroidal vacuum chamber, a toroidal coil which generates a magnetic field in a toroidal direction within the vacuum chamber, current transformer coils which are wound in the toroidal direction, equilibrium magnetic field coils which are wound in the toroidal direction in order to control a plasma, alternating current coils which are wound mainly in the toroidal direction and through which alternating currents are caused to flow for enabling forming and rotating of a deformed magnetic surface and for causing rotation of the plasma in a poloidal direction, and power sources which cause currents to flow through the various coils.

Abstract: A fusion power generating device is disclosed having a relatively small and inexpensive core region which may be contained within an energy absorbing blanket region. The fusion power core region contains apparatus of the toroidal type for confining a high density plasma. The fusion power core is removable from the blanket region and may be disposed and/or recycled for subsequent use within the same blanket region. The high density plasma produces a large radiation and particle flux on the first wall of the plasma core region thereby necessitating replacement of the core from the blanket region from time to time. A series of disposable and replaceable central core regions are disclosed for a large-scale economical electrical power generating plant.

Abstract: A fusion power generating device is disclosed having a relatively small and inexpensive core region which may be contained within an energy absorbing blanket region. The fusion power core region contains apparatus of the toroidal type for confining a high density plasma. The fusion power core is removable from the blanket region and may be disposed and/or recycled for subsequent use within the same blanket region. Thermonuclear ignition of the plasma is obtained by feeding neutral fusible gas into the plasma in a controlled manner such that charged particle heating produced by the fusion reaction is utilized to bootstrap the device to a region of high temperatures and high densities wherein charged particle heating is sufficient to overcome radiation and thermal conductivity losses. The high density plasma produces a large radiation and particle flux on the first wall of the plasma core region thereby necessitating replacement of the core from the blanket region from time to time.

Abstract: This invention provides a high power closing switch having a fast operating speed in the bypass of a main circuit switch for reducing the load share of the main circuit switch provided between a load coil and a power source circuit provided in a nuclear fusion reactor to simplify the construction of the main circuit switch formed heretofore of a number of parallel switches to reduce the value of the resistor of a clover circuit, thereby reducing the discharge current of the capacitor of the power source circuit.

Abstract: A probe for determining the energy and flux of particles in a plasma comprises a carbon film adapted to be exposed to the plasma, the film havinmg an electrical resistance which is related to the number of particles impacting the film, contacts for passing an electrical current through the film, and contacts for determining the electrical resistance of the film. An improved method for determining the energy or flux of particles in a plasma is also disclosed.

Abstract: A fusion power monitor including a circulating activation medium being activated as it passes by the fusion reaction. The radioactivity of the activation medium is sensed by a remote detector to give an indication of fusion power level.

Abstract: An inductive transformer in the form of a solenoidal coils aligned along the major axis of a flux core induces poloidal flux along the flux core's axis. The current in the solenoidal coil is then reversed resulting in a poloidal flux swing and the conversion of a portion of the poloidal flux to a toroidal flux in generating a spheromak plasma wherein equilibrium approaches a force-free, minimum Taylor state during plasma formation, independent of the initial conditions or details of the formation. The spheromak plasma is sustained with the Taylor state maintained by oscillating the currents in the poloidal and toroidal field coils within the plasma-forming flux core. The poloidal flux transformer may be used either as an amplifier stage in a moving plasma reactor scenario for initial production of a spheromak plasma or as a method for sustaining a stationary plasma and further heating it.

Abstract: A nuclear fusion reactor has a toroidal, electrically conductive shell and an air-core current transformer coil with a single turn disposed on the outer peripheral side of the shell, a plurality of port holes provided in the shell to be radially aligned with those in the coil respectively, the shell and the coil being coated with electrically insulating layers of the FBC type except for each of the port holes and its adjacent portion which are electrically insulated by one pair of electrically insulating insertions having cylindrical sections fitted into the port hole from both ends to be superposed on each other and flange sections radially extending from the opposite ends of the superposed cylindrical sections and disposed on the opposite surface portions of the shell or the coil adjacent to the port hole, and connected to the mating electrically insulating layer portions, the flange sections located on the shell and the coil to oppose to each other having terminations spaced from each other by a predetermi

Abstract: The inductively formed spheromak plasma can be maintained in a highly stable and controlled fashion. Steady-state operation is obtained by forming the plasma in the linked mode, then oscillating the poloidal and toroidal fields such that they have different phases. Preferably, the poloidal and magnetic fields are 90.degree. out of phase.

Abstract: In a magnetic plasma confinment device having an inner toroidal limiter mounted on an inner wall of a plasma containment vessel, an arrangement is provided for monitoring vertical temperature profiles of the limiter. The temperature profiles are taken at brief time intervals, in a time scan fashion. The time scans of the vertical temperature profile are continuously monitored to detect the presence of a peaked temperature excursion, which, according to the present invention, is a precursor of a subsequent major plasma disruption. A fast scan of the temperature profile is made so as to provide a time interval in real time prior to the major plasma disruption, such that corrective action can be taken to reduce the harmful effects of the plasma disruption.

Abstract: A rotating flux transformer which includes a magnetic core having poloidal primary and secondary windings and toroidal primary and secondary windings. Quadrature flux is produced in the magnetic core by connecting one end of the poloidal primary winding to the center of the toroidal primary winding. The quadrature flux combines vectorially to produce a rotating induction vector in the magnetic core.

Abstract: Apparatus and method for maintaining steady state compact toroidal plasmas. A compact toroidal plasma is formed by a magnetized coaxial plasma gun and held in close proximity to the gun electrodes by applied magnetic fields or magnetic fields produced by image currents in conducting walls. Voltage supply means maintains a constant potential across the electrodes producing an increasing magnetic helicity which drives the plasma away from a minimum energy state. The plasma globally relaxes to a new minimum energy state, conserving helicity according to Taylor's relaxation hypothesis, and injecting net helicity into the core of the compact toroidal plasma. Controlling the voltage so as to inject net helicity at a predetermined rate based on dissipative processes maintains or increases the compact toroidal plasma in a time averaged steady state mode.

Abstract: A system for generating soft X rays. This system includes valve apparatus for repetitively providing bursts of a gas of brief duration and a magnetic pulse compression power supply for providing high current pulses. The system further includes a transmission line connected to the power supply for transmitting power pulses from the supply to discharge through bursts of gas. The power supply includes a plurality of series saturable inductor magnetic switches and a plurality of shunt capacitors. Thus, upon synchronized provision of a burst of gas from the valve apparatus and a power pulse from the power supply, a high current discharge generates plasma and an intense magnetic field which radially compresses the plasma, resulting in a dense, high temperature plasma which is an intense source of soft X rays.

Abstract: Neutron activation due to high levels of neutron production in a first heated deuterium-tritium plasma is substantially reduced by using Ion Cyclotron Resonance Frequency (ICRF) heating of energetic .sup.3 He.sup.++ ions in a second deuterium-.sup.3 He.sup.++ plasma which exhibit an energy distribution and density similar to that of alpha particles in fusion reactor experiments to simulate fusion alpha particle heating in the first plasma. The majority of the fast .sup.3 He.sup.++ ions and their slowing down spectrum can be studied using either a modulated hydrogen beam source for producing excited states of He.sup.+ in combination with spectrometers or double charge exchange with a high energy neutral lithium beam and charged particle detectors at the plasma edge. The maintenance problems thus associated with neutron activation are substantially reduced permitting energetic alpha particle behavior to be studied in near term large fusion experiments.

Abstract: A limiter blade for a large tokomak fusion reactor includes three articulated blade sections for enabling the limiter blade to be adjusted for plasmas of different sizes. Each blade section is formed of a rigid backing plate carrying graphite tiles coated with titanium carbide, and the limiter blade forms a generally elliptic contour in both the poloidal and toroidal directions to uniformly distribute the heat flow to the blade. The limiter blade includes a central blade section movable along the major radius of the vacuum vessel, and upper and lower pivotal blade sections which may be pivoted by linear actuators having rollers held to the back surface of the pivotal blade sections.

Abstract: An ionizable material is ejected in the shape of a cylindrical column from a cathode-nozzle toward an anode and subjected to a very short, high voltage pulse of electrical current having sufficient magnitude to create a high magnetic field which implodes the cylindrical column of ionizable material to a very high density plasma that emits long wave length x-rays. Accurate and reliably reproduced x-ray bursts are provided through coupling of the cathode and anode to the high voltage pulse generator without substantially degrading the pulse. The conductors between the pulse generator and the cathode and anode are of a configuration whereby a magnetic field is used to prevent the electron losses by tapering the spacing between feed conductors and shaping the feed conductors so that space-charge flow is retrapped and made usable.

Abstract: This invention relates to passive conducting loops for stabilizing a plasma ring against unstable tilting and/or shifting modes. To this end, for example, plasma ring in a spheromak is stabilized by a set of four figure-8 shaped loops having one pair on one side of the plasma and one pair on the other side with each pair comprising two loops whose axes are transverse to each other.

Abstract: An inductive method and apparatus for forming detached spheromak plasma using a thin-walled metal toroidal ring, with external current leads and internal poloidal and toroidal field coils located inside a vacuum chamber filled with low density hydrogen gas and an external axial field generating coil. The presence of a current in the poloidal field coils, and an externally generated axial field sets up the initial poloidal field configuration in which the field is strongest toward the major axis of the toroid. The internal toroidal-field-generating coil is then pulsed on, ionizing the gas and inducing poloidal current and toroidal magnetic field into the plasma region in the sleeve exterior to and adjacent to the ring and causing the plasma to expand away from the ring and toward the major axis. Next the current in the poloidal field coils in the ring is reversed. This induces toroidal current into the plasma and causes the poloidal magnetic field lines to reconnect.

Abstract: An intense, space-charge-neutralized, pulsed ion beam is used to heat a metically-confined plasma, such as a tokamak plasma, by injecting the ion beam into the plasma along a trajectory that is generally tangential to the confining magnetic field. The ion beam inductively generates a plasma return current so that no net current is produced. As the ion beam drifts in the plasma, the confining magnetic field is transformed into one which can trap the ion beam at the center of the plasma. Once the ion beam is trapped, the plasma return current is cancelled by transformer action to produce a net current which is carried by the ion beam alone. The beam transfers its energy to the plasma by classical collisions with the electrons and ions of the plasma. Heating of the plasma can be sufficient to produce a breakeven condition or ignition.

Abstract: This invention relates to the control of ions orbiting in a cylindrical reaction space and more particularly to attenuation of instabilities in two counterflow streams of ions to focus the ions of both streams into a predetermined orbital reaction zone.

Abstract: A nuclear fusion system is disclosed wherein a pair of beams are to traverse common helical paths in a reaction zone. Two sources of oppositely directed gaseous ions are provided for producing the beams with means for establishing helical flow of ions in common paths whose spins are aligned in both beams.

Abstract: Apparatus is provided for controlling the plasma energy production rate of a magnetic-confinement fusion reactor, by controlling the magnetic field ripple. The apparatus includes a group of shield sectors (30a, 30b, etc.) formed of ferromagnetic material which has a temperature-dependent saturation magnetization, with each shield lying between the plasma (12) and a toroidal field coil (18). A mechanism (60) for controlling the temperature of the magnetic shields, as by controlling the flow of cooling water therethrough, thereby controls the saturation magnetization of the shields and therefore the amount of ripple in the magnetic field that confines the plasma, to thereby control the amount of heat loss from the plasma. This heat loss in turn determines the plasma state and thus the rate of energy production.

Abstract: A sensor for detecting changes in the magnetic field of the equilibrium-field coil of a Tokamak plasma device comprises a pair of bifilar wires disposed circumferentially, one inside and one outside the equilibrium-field coil. Each is shorted at one end. The difference between the voltages detected at the other ends of the bifilar wires provides a measure of changing flux in the equilibrium-field coil. This difference can be used to detect faults in the coil in time to take action to protect the coil.

Abstract: For use in a tokamak fusion reactor having a midplane magnetic coil on the inner wall of an evacuated toriodal chamber within which a neutral beam heated, fusing plasma is magnetically confined, a neutral beam armor shield and plasma limiter is provided on the inner wall of the toroidal chamber to shield the midplane coil from neutral beam shine-thru and plasma deposition. The armor shield/plasma limiter forms a semicircular enclosure around the midplane coil with the outer surface of the armor shield/plasma limiter shaped to match, as closely as practical, the inner limiting magnetic flux surface of the toroidally confined, indented, bean-shaped plasma. The armor shield/plasma limiter includes a plurality of semicircular graphite plates each having a pair of coupled upper and lower sections with each plate positioned in intimate contact with an adjacent plate on each side thereof so as to form a closed, planar structure around the entire outer periphery of the circular midplane coil.

Abstract: Measurement of the velocity distribution of confined energetic alpha particles resulting from deuterium-tritium fusion reactions in a magnetically contained plasma is provided. The fusion plasma is seeded with energetic boron neutrals for producing, by means of the reaction .sup.10 B (.alpha.,n) .sup.13 N reaction, radioactive nitrogen nuclei which are then collected by a probe. The radioactivity of the probe is then measured by conventional techniques in determining the energy distribution of the alpha particles in the plasma. In a preferred embodiment, diborane gas (B.sub.2 H.sub.6) is the source of the boron neutrals to produce .sup.13 N which decays almost exclusively by positron emission with a convenient half-life of 10 minutes.

Abstract: An arrangement is provided for the in-situ determination of energy species yields of intense particle beams. The beam is directed onto a target surface of known composition, such that Rutherford backscattering of the beam occurs. The yield-energy characteristic response of the beam to backscattering from the target is analyzed using Rutherford backscattering techniques to determine the yields of energy species components of the beam.

Abstract: A method of controlling the reaction rates of the fuel atoms in a fusion reactor comprises the step of polarizing the nuclei of the fuel atoms in a particular direction relative to the plasma confining magnetic field. Fusion reaction rates can be increased or decreased, and the direction of emission of the reaction products can be controlled, depending on the choice of polarization direction.

Abstract: Method for producing fusion power wherein a neutral beam is injected into a toroidal bulk plasma to produce fusion reactions during the time permitted by the slowing down of the particles from the injected beam in the bulk plasma.

Abstract: The plasma column in a stellarator is compressed and expanded alternatively in minor radius. First a plasma in thermal balance is compressed adiabatically. The volume of the compressed plasma is maintained until the plasma reaches a new thermal equilibrium. The plasma is then expanded to its original volume. As a result of the way a stellarator works, the plasma pressure during compression is less than the corresponding pressure during expansion. Therefore, negative work is done on the plasma over a complete cycle. This work manifests itself as a back-voltage in the toroidal field coils. Direct electrical energy is obtained from this voltage. Alternatively, after the compression step, the plasma can be expanded at constant pressure.The cycle can be made self-sustaining by operating a system of two stellarator reactors in tandem. Part of the energy derived from the expansion phase of a first stellarator reactor is used to compress the plasma in a second stellarator reactor.