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ECCD Experiments in Heliotron J: Recent Results Regarding the Dependence on Magnetic Configuration and Wave Polarization

Alvaro CAPPA, Kazunobu NAGASAKI¹⁾, Gen MOTOJIMA¹⁾, Tohru MIZUUCHI¹⁾, Hiroyuki OKADA¹⁾, Shinji KOBAYASHI¹⁾, Katsumi KONDO¹⁾, Hajime ARIMOTO¹⁾, Shinya WATANABE¹⁾, Masatoshi NOSAKU¹⁾, Hiroyuki YASUDA¹⁾, Fumimichi SANO¹⁾ and Angela FERNÁNDEZ

Laboratorio Nacional de Fusión, EURATOM-CIEMAT

1)

Institute of Advanced Energy, Kyoto University

(Received 17 March 2007 / Accepted 22 May 2007 / Published 29 June 2007)

Abstract

The electron cyclotron current drive (ECCD) is investigated in Heliotron J for two new magnetic configurations with ECRH heating located at the ripple top and the ripple bottom, respectively, using different incoming wave polarizations. The results are compared with the previous ECCD experiments, performed in the low, medium (standard) and high bumpiness configurations, where a sign reversal of the EC current is observed between the ripple top and the ripple bottom heating conditions. It is shown here that a similar behaviour is obtained in the new configurations. Positive currents are obtained when the ECR heating is located at the magnetic field minimum, whereas negative currents, but not higher in magnitude than the ones obtained in the previous experiments, appear with ripple top heating. The dependence of the ECCD on the polarization of the injected waves agrees with the expected behaviour.

Copyright (c) 2007 The Japan Society of Plasma Science and Nuclear Fusion Research

Keywords

ECCD (electron cyclotron current drive), magnetic configuration, trapped particles, Heliotron J

DOI: 10.1585/pfr.2.030

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References

• [1] K. Nagasaki et al., “Control of Non-Inductive Current in Heliotron J,” Proceedings of the 21st IAEA Conference, (Chengdu, China, 2006).
• [2] V. Tribaldos et al., Plasma Phys. Control Fusion 40, 2113 (1998).
• [3] K. Nagasaki et al., “Measurement of Single Pass EC Absorption Using Transmitted Waves in Heliotron J,” Proceedings of the 14th Joint Workshop on ECE and ECH (Santorini, Greece, 2006).

This paper may be cited as follows:

Alvaro CAPPA, Kazunobu NAGASAKI, Gen MOTOJIMA, Tohru MIZUUCHI, Hiroyuki OKADA, Shinji KOBAYASHI, Katsumi KONDO, Hajime ARIMOTO, Shinya WATANABE, Masatoshi NOSAKU, Hiroyuki YASUDA, Fumimichi SANO and Angela FERNÁNDEZ, Plasma Fusion Res. 2, 030 (2007).