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Title: Control of Current Profile and Instability by Radiofrequency Wave Injection in JT-60U and Its Applicability in JT-60SA

Abstract

Recent results of control of current profile and instability using radiofrequency wave in JT-60U and prediction analysis in JT-60SA are descried. In JT-60U, control of current profile in high-beta regime was demonstrated by using a real-time system, where the motional Stark effect diagnostic and lower hybrid wave were used as a detector and actuator, respectively. The minimum value of the safety factor was raised from 1.3 to 1.7 so as to follow the commanded value. Complete stabilization of a neoclassical tearing mode (NTM) with the poloidal mode number m = 2 and the toroidal mode number n = 1 was demonstrated using electron cyclotron (EC) current drive. By scanning the location of EC current drive in detail, strong stabilization effect was found for misalignment less than about half of the full island width. In addition, destabilization of the 2/1 NTM was observed for misalignment comparable to the full island width. Simulation of NTM stabilization in JT-60SA was performed by using the TOPICS code combined with the modified Rutherford equation. The TOPICS simulation showed that complete stabilization can be achieved more effectively by optimizing the EC wave injection angle and modulating the EC wave.

Authors:
; ; ; ; ; ; ; ; ; ; ; ; ; ;  [1];  [2]
  1. Japan Atomic Energy Agency, Naka, Ibaraki 311-0193 (Japan)
  2. Institute of Advanced Energy, Kyoto University, Uji, Kyoto 611-0011 (Japan)
Publication Date:
OSTI Identifier:
21032764
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 933; Journal Issue: 1; Conference: 17. topical conference on radio frequency power in plasmas, Clearwater, FL (United States), 7-9 May 2007; Other Information: DOI: 10.1063/1.2800482; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA). JT-60 Team
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ACTUATORS; COMPUTERIZED SIMULATION; CONTROL; ELECTRIC CURRENTS; ELECTRONS; HIGH-BETA PLASMA; JT-60U TOKAMAK; LOWER HYBRID CURRENT DRIVE; LOWER HYBRID HEATING; MAGNETIC ISLANDS; NEOCLASSICAL TRANSPORT THEORY; OPTIMIZATION; PLASMA SIMULATION; RADIOWAVE RADIATION; REAL TIME SYSTEMS; RF SYSTEMS; STABILIZATION; STARK EFFECT; TEARING INSTABILITY

Citation Formats

Isayama, A., Suzuki, T., Hayashi, N., Ide, S., Hamamatsu, K., Fujita, T., Hosoyama, H., Kamada, Y., Oyama, N., Ozeki, T., Sakata, S., Seki, M., Sueoka, M., Takechi, M., Urano, H., and Nagasaki, K. Control of Current Profile and Instability by Radiofrequency Wave Injection in JT-60U and Its Applicability in JT-60SA. United States: N. p., 2007. Web. doi:10.1063/1.2800482.
Isayama, A., Suzuki, T., Hayashi, N., Ide, S., Hamamatsu, K., Fujita, T., Hosoyama, H., Kamada, Y., Oyama, N., Ozeki, T., Sakata, S., Seki, M., Sueoka, M., Takechi, M., Urano, H., & Nagasaki, K. Control of Current Profile and Instability by Radiofrequency Wave Injection in JT-60U and Its Applicability in JT-60SA. United States. doi:10.1063/1.2800482.
Isayama, A., Suzuki, T., Hayashi, N., Ide, S., Hamamatsu, K., Fujita, T., Hosoyama, H., Kamada, Y., Oyama, N., Ozeki, T., Sakata, S., Seki, M., Sueoka, M., Takechi, M., Urano, H., and Nagasaki, K. Fri . "Control of Current Profile and Instability by Radiofrequency Wave Injection in JT-60U and Its Applicability in JT-60SA". United States. doi:10.1063/1.2800482.
@article{osti_21032764,
title = {Control of Current Profile and Instability by Radiofrequency Wave Injection in JT-60U and Its Applicability in JT-60SA},
author = {Isayama, A. and Suzuki, T. and Hayashi, N. and Ide, S. and Hamamatsu, K. and Fujita, T. and Hosoyama, H. and Kamada, Y. and Oyama, N. and Ozeki, T. and Sakata, S. and Seki, M. and Sueoka, M. and Takechi, M. and Urano, H. and Nagasaki, K.},
abstractNote = {Recent results of control of current profile and instability using radiofrequency wave in JT-60U and prediction analysis in JT-60SA are descried. In JT-60U, control of current profile in high-beta regime was demonstrated by using a real-time system, where the motional Stark effect diagnostic and lower hybrid wave were used as a detector and actuator, respectively. The minimum value of the safety factor was raised from 1.3 to 1.7 so as to follow the commanded value. Complete stabilization of a neoclassical tearing mode (NTM) with the poloidal mode number m = 2 and the toroidal mode number n = 1 was demonstrated using electron cyclotron (EC) current drive. By scanning the location of EC current drive in detail, strong stabilization effect was found for misalignment less than about half of the full island width. In addition, destabilization of the 2/1 NTM was observed for misalignment comparable to the full island width. Simulation of NTM stabilization in JT-60SA was performed by using the TOPICS code combined with the modified Rutherford equation. The TOPICS simulation showed that complete stabilization can be achieved more effectively by optimizing the EC wave injection angle and modulating the EC wave.},
doi = {10.1063/1.2800482},
journal = {AIP Conference Proceedings},
number = 1,
volume = 933,
place = {United States},
year = {Fri Sep 28 00:00:00 EDT 2007},
month = {Fri Sep 28 00:00:00 EDT 2007}
}