11th International Conference on Open Magnetic Systems for Plasma Confinement

Development of the 2MW, 30 ms neutral beam for plasma heating and stabilization in a magnetic trap

10 Aug 2016, 15:00

3h

Novosibirsk

Board: 14

Poster Plasma confinement, heating and stability Poster session

Speaker

Dr Petr Deichuli (Budker INP SB RAS)

Description

A high power, relatively low energy neutral beam injector was developed to upgrade the neutral injection system for magnetic trap. The proton or deuterium beam of the ion source has the particle energy of 15 keV and current up to 170 A at a pulse duration of 30 milliseconds. The plasma emitter of the ion source is produced by superimposing highly ionized plasma jets from an array of four arc-discharge plasma generators. A multipole magnetic field produced with permanent magnets at the periphery of the plasma box is used to increase the efficiency and improve the uniformity of the plasma emitter. Multi-slit grids with 48% transparency are fabricated from bronze plates, which are spherically shaped to provide geometrical beam focusing. The focal length of the Ion Optical System is 3.5 m and the initial beam diameter is 34.8 cm. The IOS geometry and grid potentials were optimized numerically to ensure accurate beam formation. The measured angular divergences of the beam are ±0.01 rad parallel to the slits and ±0.03 rad in the transverse direction. The content of the fullenergy fraction in the beam current exceed 90%.