title: Low energy, high power hydrogen neutral beam for plasma heating.
abstract: A high power, relatively low energy neutral beam injector was developed to upgrade of the neutral beam system of the gas dynamic trap device and C2-U experiment. The ion source of the injector produces a proton beam with the particle energy of 15 keV, current of up to 175 A, and pulse duration of a few 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 (IOS) is 3.5 m and the initial beam diameter is 34 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.
authors.affiliation: Budker Institute of Nuclear Physics, Prospect Lavrentieva 11, 630090 Novosibirsk, Russia.
authors.forename: P
authors.initials: P
authors.lastname: Deichuli
authors.affiliation: Budker Institute of Nuclear Physics, Prospect Lavrentieva 11, 630090 Novosibirsk, Russia.
authors.forename: V
authors.initials: V
authors.lastname: Davydenko
authors.affiliation: Budker Institute of Nuclear Physics, Prospect Lavrentieva 11, 630090 Novosibirsk, Russia.
authors.forename: A
authors.initials: A
authors.lastname: Ivanov
authors.affiliation: Tri Alpha Energy, Inc., Foothill Ranch, California 92610, USA.
authors.forename: S
authors.initials: S
authors.lastname: Korepanov
authors.affiliation: Budker Institute of Nuclear Physics, Prospect Lavrentieva 11, 630090 Novosibirsk, Russia.
authors.forename: V
authors.initials: V
authors.lastname: Mishagin
authors.affiliation: Tri Alpha Energy, Inc., Foothill Ranch, California 92610, USA.
authors.forename: A
authors.initials: A
authors.lastname: Smirnov
authors.affiliation: Budker Institute of Nuclear Physics, Prospect Lavrentieva 11, 630090 Novosibirsk, Russia.
authors.forename: A
authors.initials: A
authors.lastname: Sorokin
authors.affiliation: Budker Institute of Nuclear Physics, Prospect Lavrentieva 11, 630090 Novosibirsk, Russia.
authors.forename: N
authors.initials: N
authors.lastname: Stupishin