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Title: ECH-assisted startup at KSTAR

Abstract

The electron cyclotron heating (ECH)-assisted startup was successful in the Korea Superconducting Tokamak Advanced Research (KSTAR) first plasma campaign completed in June, 2008. It was observed that the second harmonic EC wave of 0.35 MW was sufficient to achieve breakdown in the ECH pre-ionization phase, to allow burn through, and to sustain the plasma during the current ramp with a low loop voltage of 2.0 V. This corresponds to a toroidal electric field of 0.24 Vm{sup -1} at the innermost vacuum vessel wall (R = 1.3 m). Since there is no feedback control of the plasma radial position in the initial phase of the KSTAR first plasma campaign, wall contact caused the plasma current fall to zero soon after the ECH beam was turned off. Extending pulse duration of the ECH power to 190 ms allowed the plasma current to rise up to more than 100 kA with a ramp-up rate of 0.8 MA/s and the pulse duration of 210 ms. Later in the first plasma campaign, the plasma was sustained up to 865 ms with the help of additional heating of 350-ms long ECH beam and with the help of the plasma radial position feedback control. The plasma currentmore » in the pre-ionization phase was observed and it is considered to be pressure-driven Pfirsch-Schlueter current.« less

Authors:
; ; ; ; ; ; ; ; ;  [1]; ; ; ;  [2]; ; ; ; ; ;  [3]
  1. National Fusion Research Institute, Gwahangno 113, Yuseong-gu, Daejeon 305-333 (Korea, Republic of)
  2. Pohang University of Science and Technology, San 31, Hyoja-dong, Nam-gu, Pohang 790-784 (Korea, Republic of)
  3. General Atomics, San Diego, CA 92121 (United States)
Publication Date:
OSTI Identifier:
21335776
Resource Type:
Journal Article
Journal Name:
AIP Conference Proceedings
Additional Journal Information:
Journal Volume: 1187; Journal Issue: 1; Conference: 18. topical conference on radio frequency power in plasmas, Gent (Belgium), 24-26 Jun 2009; Other Information: DOI: 10.1063/1.3273800; (c) 2009 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 CURRENT DRIVE; ECR HEATING; ELECTRIC CURRENTS; ELECTRIC FIELDS; ELECTRIC POTENTIAL; FEEDBACK; IONIZATION; KOREAN ORGANIZATIONS; PLASMA; PULSES; SUPERCONDUCTING MAGNETS; TOKAMAK DEVICES

Citation Formats

Bae, Y S, Joung, M, Yoon, S W, Kim, J H, Hahn, S H, Kim, W C, Yang, H L, Oh, Y K, Bak, J S, Kwon, M, Jeong, J H, Park, S I, Cho, M H, Namkung, W, Jackson, G L, Humphreys, D, Walker, M L, Gorelov, Y, Leuer, J A, and Hyatt, A W. ECH-assisted startup at KSTAR. United States: N. p., 2009. Web. doi:10.1063/1.3273800.
Bae, Y S, Joung, M, Yoon, S W, Kim, J H, Hahn, S H, Kim, W C, Yang, H L, Oh, Y K, Bak, J S, Kwon, M, Jeong, J H, Park, S I, Cho, M H, Namkung, W, Jackson, G L, Humphreys, D, Walker, M L, Gorelov, Y, Leuer, J A, & Hyatt, A W. ECH-assisted startup at KSTAR. United States. https://doi.org/10.1063/1.3273800
Bae, Y S, Joung, M, Yoon, S W, Kim, J H, Hahn, S H, Kim, W C, Yang, H L, Oh, Y K, Bak, J S, Kwon, M, Jeong, J H, Park, S I, Cho, M H, Namkung, W, Jackson, G L, Humphreys, D, Walker, M L, Gorelov, Y, Leuer, J A, and Hyatt, A W. 2009. "ECH-assisted startup at KSTAR". United States. https://doi.org/10.1063/1.3273800.
@article{osti_21335776,
title = {ECH-assisted startup at KSTAR},
author = {Bae, Y S and Joung, M and Yoon, S W and Kim, J H and Hahn, S H and Kim, W C and Yang, H L and Oh, Y K and Bak, J S and Kwon, M and Jeong, J H and Park, S I and Cho, M H and Namkung, W and Jackson, G L and Humphreys, D and Walker, M L and Gorelov, Y and Leuer, J A and Hyatt, A W},
abstractNote = {The electron cyclotron heating (ECH)-assisted startup was successful in the Korea Superconducting Tokamak Advanced Research (KSTAR) first plasma campaign completed in June, 2008. It was observed that the second harmonic EC wave of 0.35 MW was sufficient to achieve breakdown in the ECH pre-ionization phase, to allow burn through, and to sustain the plasma during the current ramp with a low loop voltage of 2.0 V. This corresponds to a toroidal electric field of 0.24 Vm{sup -1} at the innermost vacuum vessel wall (R = 1.3 m). Since there is no feedback control of the plasma radial position in the initial phase of the KSTAR first plasma campaign, wall contact caused the plasma current fall to zero soon after the ECH beam was turned off. Extending pulse duration of the ECH power to 190 ms allowed the plasma current to rise up to more than 100 kA with a ramp-up rate of 0.8 MA/s and the pulse duration of 210 ms. Later in the first plasma campaign, the plasma was sustained up to 865 ms with the help of additional heating of 350-ms long ECH beam and with the help of the plasma radial position feedback control. The plasma current in the pre-ionization phase was observed and it is considered to be pressure-driven Pfirsch-Schlueter current.},
doi = {10.1063/1.3273800},
url = {https://www.osti.gov/biblio/21335776}, journal = {AIP Conference Proceedings},
issn = {0094-243X},
number = 1,
volume = 1187,
place = {United States},
year = {2009},
month = {11}
}