CONTROL SYSTEMS FOR SUSTAINING NEUTRAL BEAM POWER SUPPLIES

AbstractA diagnostic neutral beam (DNB) is applied to measure the plasma ion temperature and rotation speed in the HT-7 tokamak. Also, a heating neutral beam (HNB) is suggested as an effective method of heating a plasma for the EAST tokamak. As a necessary step to evaluate the required beam power in both applications, the attenuation of the injected neutral beam has been numerically calculated and analyzed considering the effect of various plasma parameters, such as electron temperature, electron density, impurity concentration, and so on. Three basic atomic processes are considered here. It is shown that at the same electron density neutral beam particles can penetrate deeper at higher injection energies and a DNB with the same full energy can attenuate faster at higher electron densities. The impurity effect on the attenuation of a DNB is discussed, and the attenuation of a HNB on the EAST tokamak is also considered.

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Filament power supplies (AC-AC converters) and their design for long pulse Neutral Beam Injector of SST-1

2013 IEEE 25th Symposium on Fusion Engineering (SOFE) ◽

10.1109/sofe.2013.6635292 ◽

2013 ◽

Author(s):

Dipal Thakkar ◽

P. J. Patel ◽

V. B. Patel ◽

V. Vadher ◽

C. B. Sumod ◽

...

Keyword(s):

Power Supplies ◽

Neutral Beam ◽

Neutral Beam Injector ◽

Ac Converters ◽

Long Pulse

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

Nukleonika ◽

10.1515/nuka-2016-0069 ◽

2016 ◽

Vol 61 (4) ◽

pp. 419-423

Author(s):

Klara Mitosinkova ◽

Jan Stöckel ◽

Jozef Varju ◽

Vladimir Weinzettl

Keyword(s):

Plasma Heating ◽

High Energy ◽

Ion Source ◽

Neutral Beam ◽

Beam Power ◽

Neutral Beams ◽

Before And After ◽

Copper Shield ◽

Single Aperture ◽

Energy Components

Abstract 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 Dα 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 modified 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 modification is also presented.

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