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A 1000 keV, 5 MW, 1000 s neutral beam injector based on negative ions is being developed in the Budker Institute of Nuclear Physics, Novosibirsk in collaboration with Tri Alpha Energy, Inc. The innovative design of the injector features the spatially separated ion source and an electrostatic accelerator. Plasma or photon neutralizer and energy recuperation of the remaining ion species is employed in the injector to provide an overall energy efficiency of the system as high as 80%. A test stand for the beam acceleration is now under construction. A prototype of the negative ion beam source has been fabricated and installed at the test stand. The prototype ion source is designed to produce 120 keV, 1.5 Abeam. [ABSTRACT FROM AUTHOR]

A review of investigations in the physics and technology of ion sources, developed in the institute of Nuclear Physics in Novosibirsk is presented. Distinctive features of physical processes and technical characteristics of plasma sources of gaseous ions, negative ion surface-plasma sources, electrohydrodynamic (liquid metal) ion sources are considered. In original design plasma sources, ion beams with a current of up to 90 A and energies 1-30 keV are formed by fourelectrode multislit extraction systems from highly ionized, high brightness plasma flux, generated by an high-current arc discharge with a cold cathode in a small cross-section diaphragmed channel, and directed with a magnetic field ora special configuration. Plasma jet expansion for a very low ion temperature (0.1 eV) production is used. In surface plasma sources, the fluxes of negative ions are produced when electrons are captured from the electrode surface at the electron affinity level of sputtered and reflected particles. A discharge of a special type in a gas-cesium mixture with a thin plasma layer between the negative ion emitter and emission holes is used. A number of versions of SPS with different types of discharges are considered: SPS which operate in pulse mode with H[sup -] beam current up to 11 A, with current 0.1 A, and high brightness for accelerators, for continuous mode operation. Specific features of physical processes in electrohydrodynamic (EHD) ion emitters are studied and the technology of production of different ions is worked out. The production of ion beams with high brightness from the dielectric melt in the EHD-emission regime is developed. The dynamics of spontaneous oscillation excitation with a quasidiscrete spectrum in the frequency range of up to 10[sup 8] Hz, transient processes occurring at the emission disturbances, emission stability at low current, a physical model for calculating the emission surface dimensions, and the evolution of the ion momentum distribution... [ABSTRACT FROM AUTHOR]

Experimental data on the dynamics of cesium particles in the pulsed magnetron and Penning surface-plasma ion sources are presented. Cesium escape from the source emission apertures and the cesium ion current to discharge electrodes was measured. The low value of cesium flux from the source was detected. An intense cesium ion current to the cathode (up to 0.8 A/cm2) was measured. The high value of cesium ion current to surface-plasma source cathode confirms the cesium circulation near the cathode. [ABSTRACT FROM AUTHOR]

A cesiated hydrogen hollow cathode (CHC) was tested for plasma injection in the multicusp negative ion source (MS). The CHC arc with hydrogen feed and cesium seeding through the CHC volume was explored. One cathode unit (40 mm length, 19 mm in diameter, emission opening area 1-3 mm²) with no special cooling provided the MS discharge operation with direct current up to 30 A, and up to 60 A in the long-pulse mode. High efficiency of negative ion production in the MS discharge, driven by a CHC plasma injection was recorded. [ABSTRACT FROM AUTHOR]

Examines cesium recovery from the polluted layers by additional discharges in the 1/3 scale hydrogen negative ion source for LHD-NBI system. Mechanism of recovery; Ejection of cesium from the underlying enriched layer by the arc and its transport to the surface.

Evaluates the multibeam honeycomb surface-plasma source with plasma injection from hollow cathodes. Use of the plasma injection for a high-current semiplanotron discharge uniform operation; Production of elementary negative hydrogen beams through ion extraction from the emission apertures; Consistency of the intensity of negative deuterium beams.

Two types of the surface-plasma sources of negative hydrogen ions developed at Budker Institute of Nuclear Physics are discussed. The source characteristics and the mechanism of negative ion production are presented. It is shown that several channels of plasma particle surface conversion and desorption are responsible for an intense negative ion production in these sources. The results of a detailed study of the quasistationary honeycomb and its comparison with the data for hollow-cathode Penning sources are presented. [ABSTRACT FROM AUTHOR]

A compact steady-state negative ion source using a hollow cathode Penning discharge is described. Water-cooled gas-discharge electrodes and permanent Sm-Co magnets were used. Steady-state source operation with a H[sup -] beam current intensity of up to 50 mA and discharge power of up to 0.8 kW was achieved. The H[sup -] current density in the emission holes was about 50 mA/cm². The gas efficiency was 3%. The H[sup -] yield was proportional to the area of the emission apertures and to the discharge current. About 10 mA of H[sup -] beam was accelerated and transported with the source having a smaller emission hole area of 0.3 cm² in the tests at the Ecole Polytechnique accelerator facility. [ABSTRACT FROM AUTHOR]

Long-pulsed surface plasma multiaperture models with hydrogen negative-ions output of up to 1 A and with an average current density of 60 mA/cm² are described. The experimental and simulated negative-ion production efficiencies of pure hydrogen and cesiated surface-plasma sources with geometrical focusing are compared. [ABSTRACT FROM AUTHOR]

The pulsed operation of a negative ion volume source has been investigated, both with and without a magnetic filter present, under conditions of full-scale acceleration of the extracted negative hydrogen ion beam. This investigation is relevant to the temporal filter concept, which was recently proposed. The observation of three afterglow negative ion peaks is reported. As the negative ion current during the discharge pulse, each of the afterglow peaks can be optimized by varying the pressure, the plasma electrode bias, and the extraction voltage. Under optimum conditions, the negative ion current during the discharge pulse exceeds the afterglow peaks. [ABSTRACT FROM AUTHOR]

Presents the compact cesium (Cs) coating system which was used for the direct deposition of Cs atoms and ions onto the inner surface of a third scale hydrogen negative ion source for the large helical device-neutral beam injection system. Beam current evolution after Cs depositions; Effect of temperature on hydrogen current.