Energy composition of high-energy neutral beams on the COMPASS tokamak

0464276 - ÚFP 2017 RIV PL eng J - Journal Article
Bogár, Klára - Stöckel, Jan - Varju, Jozef - Weinzettl, Vladimír
Energy composition of high-energy neutral beams on the COMPASS tokamak.
Nukleonika. Roč. 61, č. 4 (2016), s. 419-423. ISSN 0029-5922. E-ISSN 1508-5791.
[Summer School of Plasma Diagnostics PhDiaFusion 2015: “Soft X-ray Diagnostics for Fusion Plasma”. Bezmiechowa, 16.06.2015-20.06.2015]
R&D Projects: GA MŠMT(CZ) LM2011021; GA MŠMT(CZ) 8D15001
Institutional support: RVO:61389021
Keywords : tokamak * neutral beam injection (NBI) * Doppler effect * beam composition * beam composition
Subject RIV: BL - Plasma and Gas Discharge Physics
Impact factor: 0.760, year: 2016
http://www.ichtj.waw.pl/nukleonikaa/?p=1256

The COMPASS tokamak is equipped with two identical neutral beam injectors (NBI) for additional plasma heating. They provide a beam of deuterium atoms with a power of up to ~(2 × 300) kW. We show that the neutral beam is not monoenergetic but contains several energy components. An accurate knowledge of the neutral beam power in each individual energy component is essential for a detailed description of the beam--plasma interaction and better understanding of the NBI heating processes in the COMPASS tokamak. This
paper describes the determination of individual energy components in the neutral beam from intensities of the
Doppler-shifted D lines, which are measured by a high-resolution spectrometer viewing the neutral beam-line
at the exit of NBI. Furthermore, the divergence of beamlets escaping single aperture of the last accelerating
grid is deduced from the width of the Doppler-shifted lines. Recently, one of the NBI systems was modifi ed by
the removal of the Faraday copper shield from the ion source. The comparison of the beam composition and the
beamlet divergence before and after this modifi cation is also presented.
Permanent Link: http://hdl.handle.net/11104/0263225