ISSN:
1089-7623
Source:
AIP Digital Archive
Topics:
Physics
,
Electrical Engineering, Measurement and Control Technology
Notes:
Low-divergent quasistationary neutral beams are often applied in modern magnetic fusion devices as a diagnostic tool providing unique information about plasma parameters. The most important requirements of these beams are sufficiently large current and energy of the particles, so that the beam can penetrate to the plasma core. Also the duration of the beams must be long enough, i.e., close to that of a plasma discharge, amounting to at least a few seconds for large fusion devices. We developed a neutral beam injector for plasma diagnostics in the tokamak TEXTOR-94 which is capable of meeting these requirements. The maximum beam energy is 50 keV and the source operated in hydrogen delivers an ion current of up to 2 A with a pulse duration of up to 4 s. The low divergent beam (∼0.5°– 0.6°) is geometrically focused 4 m downstream from the source having a 1/e width of ∼ 70 mm at the focal point. The beam can be modulated with a frequency variable up to 500 Hz. The ion source plasma is produced by a radio frequency discharge in hydrogen or helium. The ion beam is extracted by a four-grid system with 163 single holes. The measured beam parameters were compared with those predicted by simulations. © 2000 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.1289681
Permalink
