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Title: Initial ICRF heating experiments on the LHD

Abstract

The final goal of Ion Cyclotron Range of Frequency (ICRF) heating on the Large Helical Device (LHD) is characterized by its high power (up to 12MW) and by steady state operation (30 minutes). Initial ICRF heating experiments were carried out using a pair of loop antemas in the 2nd experimental campaign in 1998. The ICRF heating power was applied to an ECH-produced plasma at an RF power level of 300 kW for 0.2 seconds. An applied frequency of f=25.6 MHz was selected. A cyclotron resonance layer of hydrogen ions was located at the half minor radius during operation at B=1.5 T. A mode conversion layer of a He plasma with a minority of hydrogen ions was located between the magnetic axis and the last closed magnetic flux. The plasma stored energy was observed to increase to twice that of the ECH plasma (P{sub ECH}=300 kW). The plasma stored energy of the ECH target plasma was 11-13 kJ at an average electron density of n{sub e}=8-9x10{sup 18} m{sup -3} and a central electron temperature of T{sub e0}=400 eV. The plasma stored energy increased by 13 kJ with the application of ICRF heating at n{sub e}=7-8x10{sup 18} m{sup -3} and T{sub e0}=700more » eV. A strong electron heating via mode conversion was observed at a higher minority ratio of hydrogen ions.« less

Authors:
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;  [1]
  1. National Institute for Fusion Science, Toki, 509-5292 (Japan) (and others)
Publication Date:
OSTI Identifier:
21210444
Resource Type:
Journal Article
Journal Name:
AIP Conference Proceedings
Additional Journal Information:
Journal Volume: 485; Journal Issue: 1; Conference: 13. topical conference on radio frequency power in plasmas, Annapolis, MD (United States), 12-14 Apr 1999; Other Information: DOI: 10.1063/1.59742; (c) 1999 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0094-243X
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ECR HEATING; ELECTRON DENSITY; ELECTRON TEMPERATURE; EV RANGE; HYDROGEN IONS; ICR HEATING; ION TEMPERATURE; LHD DEVICE; MAGNETIC FLUX; MHZ RANGE; MODE CONVERSION; OPERATION; PLASMA; RF SYSTEMS; STEADY-STATE CONDITIONS; STORED ENERGY; TOKAMAK DEVICES

Citation Formats

Kumazawa, R., Mutoh, T., Seki, T., Shimpo, F., Nomura, G., Watari, T., Ohkubo, K., Sato, M., Kubo, S, Shimozuma, T., Idei, H., Yoshimura, Y., Kaneko, O., Takeiri, Y., Oka, Y., Tsumori, K., Osakabe, M., Ohyabu, N., Kawahata, K., and Komori, A. Initial ICRF heating experiments on the LHD. United States: N. p., 1999. Web. doi:10.1063/1.59742.
Kumazawa, R., Mutoh, T., Seki, T., Shimpo, F., Nomura, G., Watari, T., Ohkubo, K., Sato, M., Kubo, S, Shimozuma, T., Idei, H., Yoshimura, Y., Kaneko, O., Takeiri, Y., Oka, Y., Tsumori, K., Osakabe, M., Ohyabu, N., Kawahata, K., & Komori, A. Initial ICRF heating experiments on the LHD. United States. doi:10.1063/1.59742.
Kumazawa, R., Mutoh, T., Seki, T., Shimpo, F., Nomura, G., Watari, T., Ohkubo, K., Sato, M., Kubo, S, Shimozuma, T., Idei, H., Yoshimura, Y., Kaneko, O., Takeiri, Y., Oka, Y., Tsumori, K., Osakabe, M., Ohyabu, N., Kawahata, K., and Komori, A. Mon . "Initial ICRF heating experiments on the LHD". United States. doi:10.1063/1.59742.
@article{osti_21210444,
title = {Initial ICRF heating experiments on the LHD},
author = {Kumazawa, R. and Mutoh, T. and Seki, T. and Shimpo, F. and Nomura, G. and Watari, T. and Ohkubo, K. and Sato, M. and Kubo, S and Shimozuma, T. and Idei, H. and Yoshimura, Y. and Kaneko, O. and Takeiri, Y. and Oka, Y. and Tsumori, K. and Osakabe, M. and Ohyabu, N. and Kawahata, K. and Komori, A.},
abstractNote = {The final goal of Ion Cyclotron Range of Frequency (ICRF) heating on the Large Helical Device (LHD) is characterized by its high power (up to 12MW) and by steady state operation (30 minutes). Initial ICRF heating experiments were carried out using a pair of loop antemas in the 2nd experimental campaign in 1998. The ICRF heating power was applied to an ECH-produced plasma at an RF power level of 300 kW for 0.2 seconds. An applied frequency of f=25.6 MHz was selected. A cyclotron resonance layer of hydrogen ions was located at the half minor radius during operation at B=1.5 T. A mode conversion layer of a He plasma with a minority of hydrogen ions was located between the magnetic axis and the last closed magnetic flux. The plasma stored energy was observed to increase to twice that of the ECH plasma (P{sub ECH}=300 kW). The plasma stored energy of the ECH target plasma was 11-13 kJ at an average electron density of n{sub e}=8-9x10{sup 18} m{sup -3} and a central electron temperature of T{sub e0}=400 eV. The plasma stored energy increased by 13 kJ with the application of ICRF heating at n{sub e}=7-8x10{sup 18} m{sup -3} and T{sub e0}=700 eV. A strong electron heating via mode conversion was observed at a higher minority ratio of hydrogen ions.},
doi = {10.1063/1.59742},
journal = {AIP Conference Proceedings},
issn = {0094-243X},
number = 1,
volume = 485,
place = {United States},
year = {1999},
month = {9}
}