Modification of argon impurity transport by electron cyclotron heating in KSTAR H-mode plasmas

Joohwan Hong, S.S. Henderson, Kimin Kim, C.R. Seon, Inwoo Song, H.Y. Lee, Juhyeok Jang, Jae Sun Park, S.G. Lee, J.H. Lee, Seung Hun Lee, Suk-Ho Hong, Wonho Choe

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

Experiments with a small amount of Ar gas injection as a trace impurity were conducted in the Korea Superconducting Tokamak Advanced Research (KSTAR) H-mode plasma (BT  = 2.8 T, IP = 0.6 MA, and PNBI = 4.0 MW). 170 GHz electron cyclotron resonance heating (ECH) at 600 and 800 kW was focused along the mid-plane with a fixed major radial position of R  =  1.66 m. The emissivity of the Ar16+ (3.949 Å) and Ar15+ (353.860 Å) spectral lines were measured by x-ray imaging crystal spectroscopy (XICS) and a vacuum UV (VUV) spectrometer, respectively. ECH reduces the peak Ar15+ emission and increases the Ar16+ emission, an effect largest with 800 kW. The ADAS-SANCO impurity transport code was used to evaluate the Ar transport coefficients. It was found that the inward convective velocity found in the plasma core without ECH was decreased with ECH, while diffusion remained approximately constant resulting in a less-peaked Ar density profile. Theoretical results from the NEO code suggest that neoclassical transport is not responsible for the change in transport, while the microstability analysis using GKW predicts a dominant ITG mode during both ECH and non-ECH plasmas.
LanguageEnglish
Article number036028
Pages1-10
Number of pages10
JournalNuclear Fusion
Volume57
Issue number3
DOIs
Publication statusPublished - 6 Feb 2017

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electron cyclotron heating
Korea
electron cyclotron resonance
argon
impurities
heating
near Earth objects
gas injection
plasma heating
cyclotron resonance
emissivity
line spectra
transport properties
spectrometers
vacuum
profiles
spectroscopy
crystals
x rays

Keywords

  • argon
  • spectroscopy
  • plasma

Cite this

Hong, J., Henderson, S. S., Kim, K., Seon, C. R., Song, I., Lee, H. Y., ... Choe, W. (2017). Modification of argon impurity transport by electron cyclotron heating in KSTAR H-mode plasmas. Nuclear Fusion, 57(3), 1-10. [036028]. https://doi.org/10.1088/1741-4326/aa5333
Hong, Joohwan ; Henderson, S.S. ; Kim, Kimin ; Seon, C.R. ; Song, Inwoo ; Lee, H.Y. ; Jang, Juhyeok ; Park, Jae Sun ; Lee, S.G. ; Lee, J.H. ; Lee, Seung Hun ; Hong, Suk-Ho ; Choe, Wonho. / Modification of argon impurity transport by electron cyclotron heating in KSTAR H-mode plasmas. In: Nuclear Fusion. 2017 ; Vol. 57, No. 3. pp. 1-10.
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title = "Modification of argon impurity transport by electron cyclotron heating in KSTAR H-mode plasmas",
abstract = "Experiments with a small amount of Ar gas injection as a trace impurity were conducted in the Korea Superconducting Tokamak Advanced Research (KSTAR) H-mode plasma (BT  = 2.8 T, IP = 0.6 MA, and PNBI = 4.0 MW). 170 GHz electron cyclotron resonance heating (ECH) at 600 and 800 kW was focused along the mid-plane with a fixed major radial position of R  =  1.66 m. The emissivity of the Ar16+ (3.949 {\AA}) and Ar15+ (353.860 {\AA}) spectral lines were measured by x-ray imaging crystal spectroscopy (XICS) and a vacuum UV (VUV) spectrometer, respectively. ECH reduces the peak Ar15+ emission and increases the Ar16+ emission, an effect largest with 800 kW. The ADAS-SANCO impurity transport code was used to evaluate the Ar transport coefficients. It was found that the inward convective velocity found in the plasma core without ECH was decreased with ECH, while diffusion remained approximately constant resulting in a less-peaked Ar density profile. Theoretical results from the NEO code suggest that neoclassical transport is not responsible for the change in transport, while the microstability analysis using GKW predicts a dominant ITG mode during both ECH and non-ECH plasmas.",
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author = "Joohwan Hong and S.S. Henderson and Kimin Kim and C.R. Seon and Inwoo Song and H.Y. Lee and Juhyeok Jang and Park, {Jae Sun} and S.G. Lee and J.H. Lee and Lee, {Seung Hun} and Suk-Ho Hong and Wonho Choe",
note = "This is an author-created, un-copyedited version of an article accepted for publication in Nuclear Fusion. The publisher is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at https://doi.org/10.1088/1741-4326/aa5333.",
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Hong, J, Henderson, SS, Kim, K, Seon, CR, Song, I, Lee, HY, Jang, J, Park, JS, Lee, SG, Lee, JH, Lee, SH, Hong, S-H & Choe, W 2017, 'Modification of argon impurity transport by electron cyclotron heating in KSTAR H-mode plasmas' Nuclear Fusion, vol. 57, no. 3, 036028, pp. 1-10. https://doi.org/10.1088/1741-4326/aa5333

Modification of argon impurity transport by electron cyclotron heating in KSTAR H-mode plasmas. / Hong, Joohwan; Henderson, S.S.; Kim, Kimin; Seon, C.R.; Song, Inwoo; Lee, H.Y.; Jang, Juhyeok; Park, Jae Sun; Lee, S.G.; Lee, J.H.; Lee, Seung Hun; Hong, Suk-Ho; Choe, Wonho.

In: Nuclear Fusion, Vol. 57, No. 3, 036028, 06.02.2017, p. 1-10.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Modification of argon impurity transport by electron cyclotron heating in KSTAR H-mode plasmas

AU - Hong, Joohwan

AU - Henderson, S.S.

AU - Kim, Kimin

AU - Seon, C.R.

AU - Song, Inwoo

AU - Lee, H.Y.

AU - Jang, Juhyeok

AU - Park, Jae Sun

AU - Lee, S.G.

AU - Lee, J.H.

AU - Lee, Seung Hun

AU - Hong, Suk-Ho

AU - Choe, Wonho

N1 - This is an author-created, un-copyedited version of an article accepted for publication in Nuclear Fusion. The publisher is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at https://doi.org/10.1088/1741-4326/aa5333.

PY - 2017/2/6

Y1 - 2017/2/6

N2 - Experiments with a small amount of Ar gas injection as a trace impurity were conducted in the Korea Superconducting Tokamak Advanced Research (KSTAR) H-mode plasma (BT  = 2.8 T, IP = 0.6 MA, and PNBI = 4.0 MW). 170 GHz electron cyclotron resonance heating (ECH) at 600 and 800 kW was focused along the mid-plane with a fixed major radial position of R  =  1.66 m. The emissivity of the Ar16+ (3.949 Å) and Ar15+ (353.860 Å) spectral lines were measured by x-ray imaging crystal spectroscopy (XICS) and a vacuum UV (VUV) spectrometer, respectively. ECH reduces the peak Ar15+ emission and increases the Ar16+ emission, an effect largest with 800 kW. The ADAS-SANCO impurity transport code was used to evaluate the Ar transport coefficients. It was found that the inward convective velocity found in the plasma core without ECH was decreased with ECH, while diffusion remained approximately constant resulting in a less-peaked Ar density profile. Theoretical results from the NEO code suggest that neoclassical transport is not responsible for the change in transport, while the microstability analysis using GKW predicts a dominant ITG mode during both ECH and non-ECH plasmas.

AB - Experiments with a small amount of Ar gas injection as a trace impurity were conducted in the Korea Superconducting Tokamak Advanced Research (KSTAR) H-mode plasma (BT  = 2.8 T, IP = 0.6 MA, and PNBI = 4.0 MW). 170 GHz electron cyclotron resonance heating (ECH) at 600 and 800 kW was focused along the mid-plane with a fixed major radial position of R  =  1.66 m. The emissivity of the Ar16+ (3.949 Å) and Ar15+ (353.860 Å) spectral lines were measured by x-ray imaging crystal spectroscopy (XICS) and a vacuum UV (VUV) spectrometer, respectively. ECH reduces the peak Ar15+ emission and increases the Ar16+ emission, an effect largest with 800 kW. The ADAS-SANCO impurity transport code was used to evaluate the Ar transport coefficients. It was found that the inward convective velocity found in the plasma core without ECH was decreased with ECH, while diffusion remained approximately constant resulting in a less-peaked Ar density profile. Theoretical results from the NEO code suggest that neoclassical transport is not responsible for the change in transport, while the microstability analysis using GKW predicts a dominant ITG mode during both ECH and non-ECH plasmas.

KW - argon

KW - spectroscopy

KW - plasma

UR - http://iopscience.iop.org/journal/0029-5515

U2 - 10.1088/1741-4326/aa5333

DO - 10.1088/1741-4326/aa5333

M3 - Article

VL - 57

SP - 1

EP - 10

JO - Nuclear Fusion

T2 - Nuclear Fusion

JF - Nuclear Fusion

SN - 0029-5515

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M1 - 036028

ER -