High harmonic electron cyclotron resonance heating in the Large Helical Device

Gasparino, U.; Idei, H.; Kubo, S.; Marushchenko, N. B.; Romé, M.

doi:10.1088/0029-5515/38/2/306

Cited by 7 publications

(9 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This is almost an order of magnitude larger as compared with case 2, where the loop voltage changes only by about ±7-10 mV (figure 8, top, right) and the driven EC-current is only about 0.8 A kW −1 (figure 8, bottom, right). The CD efficiency is calculated from linear theory with trapped particle effects included [27,28] and taking into account the measured profiles of n e and T e for each discharge of the scan.…”

Section: Electron Cyclotron Current Drivementioning

confidence: 99%

20 years of ECRH at W7-A and W7-AS

et al. 2003

View full text Add to dashboard Cite

Basic research on high-power ECRH started 20 years ago at IPP using 28 GHz pulses with 200 kW for 40 ms at the W7-A stellarator. These pilot experiments triggered a strong activity of exploration of the unique capabilities of localized heating and current drive. The achievements in physics were strongly linked with progress in source and transmission line technology. The capability and versatility of ECRH are reviewed using W7-A and W7-AS as example experiments; the latter was shut down on July 31, 2002. The milestone achievements are discussed. Standard heating scenarios such as O-mode and X-mode as well as advanced scenarios like mode-conversion heating via the O–X–B process at different harmonics were investigated and selected results are presented. First experiments with current drive by Bernstein-waves are reported. The physics of wave interaction with stellarator-specific trapped particle populations is discussed. The results from W7-A and W7-AS establish the experimental and technological bases for the 10 MW, CW ECRH system at W7-X, which aims to demonstrate the inherent steady-state capability of stellarators.

show abstract

Section: Electron Cyclotron Current Drivementioning

confidence: 99%

20 years of ECRH at W7-A and W7-AS

et al. 2003

View full text Add to dashboard Cite

show abstract

“…In the past, low-power measurements of the emission/ absorption characteristics at the third harmonic were reported [4][5][6]. A high-harmonic ECRH for plasma startup and heating was also theoretically investigated on the large helical device (LHD) [7]. This paper is the first report on the high-power heating of a tokamak plasma at the third harmonic: 1.5 MW of X3 power were injected in TCV.…”

Section: Introductionmentioning

confidence: 98%

Preliminary results of top launch third harmonic X-mode electron cyclotron heating in the TCV tokamak

Hogge¹,

Alberti²,

Porte³

et al. 2003

Nucl. Fusion

View full text Add to dashboard Cite

The electron cyclotron heating (ECH) system in TCV has recently been upgraded to a total of 4.5 MW of installed power. In order to extend the density range of ECH-heated plasmas up to electron densities of 1.2 × 1020 m−3, three 0.5 MW gyrotrons at a frequency of 118 GHz have been added to the existing 3 MW second harmonic system operating at a frequency of 82.7 GHz. The launcher consists of a mirror placed at the top of the vessel that collects the power of the three microwave sources and can be steered radially and poloidally to ensure maximum flexibility. The choice of the top launch scheme results as a compromise between heating of high-density plasmas and maximization of single-pass absorption in Ohmically heated target plasmas. In this launching configuration, the high sensitivity of single-pass absorption to launching geometry has been experimentally demonstrated. A comparison between the experimental results and the linear ray-tracing/absorption code TORAY-GA shows a good agreement for densities up to 6.0 × 1019 m−3.

show abstract

“…Under this condition, the ray can remain resonant with electrons over a considerable length. Therefore, good absorption is expected over a wide density range even for the third-harmonic resonance heating by the linear theory [1].…”

Section: Introductionmentioning

confidence: 99%

Efficient Heating at the Third-Harmonic Electron Cyclotron Resonance in the Large Helical Device

Shimozuma

Kubo

Igami

et al. 2008

Plasma and Fusion Research

View full text Add to dashboard Cite

Efficient heating at the third-harmonic electron cyclotron resonance was attained by injection of millimeterwave power with 84 GHz frequency range at the magnetic field strength of 1 T in LHD. The electron temperature at the plasma center clearly increased, and the increment in the temperature reached 0.2-0.3 keV. The dependence of the power absorption rate on the antenna focal position was investigated experimentally, showing that the optimum position was located in the slightly high-field side of the resonance layer. Ray-tracing calculation was performed in the realistic three-dimensional magnetic configuration, and its results are compared with the experimental results.

show abstract

High harmonic electron cyclotron resonance heating in the Large Helical Device

Cited by 7 publications

References 17 publications

20 years of ECRH at W7-A and W7-AS

20 years of ECRH at W7-A and W7-AS

Preliminary results of top launch third harmonic X-mode electron cyclotron heating in the TCV tokamak

Efficient Heating at the Third-Harmonic Electron Cyclotron Resonance in the Large Helical Device

Contact Info

Product

Resources

About