RESUMEN
An injector of fast deuterium atoms for plasma heating was designed and installed at the Tokamak à Configuration Variable (TCV). The neutral beam can deliver 1 MW power to the plasma in 2 s pulses. An ion beam of the injector is formed by a triode multislit ion-optical system with spherical electrodes which provide ballistic focusing. Tests at TCV revealed that the total angular divergence of the neutral beam across the slits exceeded the expected value more than twice. It was finally established that this increase in divergence was caused by the asymmetry of the chamfers at the slit edges of the plasma electrode. The redesigned shape of the slits of the plasma grid together with precise machining significantly improved the beam quality. Experimental testing proved that the neutral beam profile in the direction across the grid slits became very close to the expected value.
RESUMEN
A plane cathode composed of close-packed hexagonal LaB6 (lanthanum hexaboride) segments is described. The 6 cm diameter circular cathode is heated by radiation from a graphite foil flat spiral. The cathode along with a hollow copper anode is used for the arc discharge plasma production in a newly developed linear plasma device. A separately powered coil located around the anode is used to change the magnetic field strength and geometry in the anode region. Different discharge regimes were realized using this coil.
