Details of the confinement primary ionizing electrons and plasma by multidipole fields are given. It is shown that very efficiently confined cusps, with leakage half-widths given electron gyroradii. Plasma much more weakly. Leakage helium, argon, xenon plasmas found to be twice hydrid noise in neighborhood hybrid frequency observed cusp regions.

H− ions formed by volume processes are extracted from a multicusp ion source. It is shown that permanent magnet filter together with small positive bias voltage on the plasma grid can produce very significant reduction in electron drain as well sizable increase available for extraction. A further current achieved installing pair of ceramic magnets at extraction aperture. The combined arrangement improves ratio to about unity.

Hydrogen ion species and discharge characteristics have been compared for two different magnet geometries in a multicusp source. One configuration indicated that the H2+ percentage extracted beam could be reduced by eliminating high energy ionizing electrons near extraction region. To accomplish this maintain desired features of both geometries, magnetic filter was installed source exit. With combined arrangement, we found H+ condition were much improved more uniform density profile across...

A large multicusp negative ion source has been constructed to generate H− or D− ions for high-energy neutral beam systems. With the presence of cesium, produced a steady-state current greater than 1 with an impurity level less 1%. The vertical and horizontal profiles self-extracted have measured gridded Faraday cup. gas efficiency electron component in accelerated two different pumping conditions.

The performance of a cubical permanent magnet generated line-cusp ion source has been investigated for use with neutral beam injectors. This operated discharge currents greater than 500 A and current densities higher 400 mA/cm2 at the extraction grid. uniformity density profile across area is found to be dependent on gas pressure. By using fast Langmuir probe sweeping circuit, electron temperature plasma potential have analyzed different powers pressures. heat load grid when it electrically...

The characteristics of a steady state, surface conversion, multiline-cusp negative ion source have been investigated for the production high-energy neutral beams. With presence cesium, this has operated at pressure 1×10−3 Torr to generate H− current greater than 400 mA. percentage impurities in self-extracted beam analyzed by mass spectrometer. A technique reducing background electron density exit is also presented.

The effect on H− ion production by adding cesium or xenon to a hydrogen discharge, in small magnetically filtered multicusp source, has been investigated. Addition of vapor the discharge resulted factor 16 increase output relative uncesiated for same operating parameters. Likewise, addition gas 2.7 over pure operation at optimum H2 source pressure, while maintaining arc Operation with plasma electrode bias voltage was essential obtain this result.

Recent experimental investigations have demonstrated that a substantial amount of H-or D- ions can be produced by thermal desorption processes. Based on these new findings, mini neutron sources now developed to produce high-energy neutrons via the d-10B nuclear reaction. By operating tubes with high frequency AC high-voltage supply, short pulses intensity beams generated. The should suitable for compensated porosity and carbon/oxygen ratio measurements in oil well logging. It is shown...

A small multicusp source has been developed to generate volume-produced H− ion beams in pulsed operation. To obtain high current densities (J−>250 mA/cm2), this requires relatively gas pressure and discharge power. Experiments have conducted improve the arc efficiencies, beam pulse shape, electron ratio extracted by optimizing filter magnetic field, thickness axial position of extraction aperture plasma electrode, mixing xenon or other elements with hydrogen discharge. The biggest...

An rf driven multicusp source capable of generating 1-ms H− beam pulses with a repetition rate as high 150 Hz has been developed. This can be operated filament or other types starter. There is almost no lifetime limitation and clean plasma maintained for long period operation. It demonstrated that power 25 kW could coupled inductively to the via glass-coated copper-coil antenna. The extracted current density achieved about 200 mA/cm2.

The magnetic multipole line-cusp device developed by MacKenzie and associates has been adapted for use as a neutral beam ion source. It produced high-density, large volume, quiescent, uniform hydrogen plasmas, which makes it potential candidate plasma generator injectors. is water-cooled cylindrical copper discharge chamber (25 cm in diameter 36 long) with one end enclosed set of extraction grids 15-cm-diam multi-aperture pattern. wall serves an anode surrounded external system rare-earth...

The properties of a steady-state, dc discharge multidipole ion source have been investigated. plasma density in the depends on magnet geometries, voltage, and bias voltage first extraction grid. Different schemes to reduce loss ions chamber wall are described. Hydrogen species extracted beam studied by mass analyzer.

Different techniques to increase the H− yield in a multicusp source have been investigated. It is shown that extracted current can be enhanced by optimizing discharge voltage, neutral gas pressure, or employing magnetoelectrostatic containment scheme. A factor of 6 output has achieved placing extractor very close magnetic filter. also found electron much reduced at this optimum geometry.

Some physical properties of lanthanum hexaboride filaments, when operated as cathodes in a gas discharge, are presented. These directly heated hairpin-shaped filaments have been tested different types ion sources and shown to be capable long-pulse or cw discharge operations. The design shaped filament for the purpose further extension lifetime is also described.

H− ions produced by volume processes have been extracted from a multicusp source operated with magnetic filter and accelerated to form high-quality beam. It was found that the beam current increased almost linearly discharge current. An ion density of 38 mA/cm2 obtained approximately 350 A. The mass analyzed emittance component measured. electron percentage impurity in were also determined.

High-quality H− beams have been generated from a multicusp source equipped with permanent magnet filter. It is shown that large improvement in yield can be achieved by employing small source, fabricated the proper wall material and extraction chamber length. From this current densities higher than 250 mA/cm2 extracted 1-mm-diam aperture for discharge voltage of 150 V 450 A. When operated deuterium, extractable negative ion density reduced approximately 30%.

The H− ion density is measured by photodetachment in the source and target sections of a tandem multicusp discharge containing ‘‘magnetic filter.’’ results confirm previous observations based on measurement extracted currents, that magnetic filter, together with small positive bias plasma grid, produce significant increase reduction electron section.

Some physical properties of tungsten filaments, when operated as cathodes in a gas discharge, are presented. For 0.1524-cm-diam wire, the initiation discharge is found to be dependent on filament geometry. The effect connecting power supply either positive or negative leg examined. When emission current becomes sizable fraction heater current, does not emit uniformly. temperature distribution indicates that majority electrons emitted from filament.

Recent experimental investigations have demonstrated that a substantial amount of H−/D− ions can be formed by thermal desorption processes. Based on these new findings, mini axial and coaxial-type neutron tubes been developed for the production high or low-energy neutrons via d-d, d-10B, d-7Li p-7Li nuclear reactions. By operating with frequency AC high-voltage supply, short pulses intensity beams generated. Multiple applications, such as carbon well logging, imaging, cancer therapy, medical...