Initial results of H-mode edge pedestal turbulence evolution with quadrature reflectometer measurements on DIII-D

G. Wang; W. A. Peebles; E. J. Doyle; T. L. Rhodes; L. Zeng; X. Nguyen; T. H. Osborne; P. B. Snyder; G. J. Kramer; R. Nazikian; R. J. Groebner; K. H. Burrell; A. W. Leonard; M. E. Fenstermacher; E. J. Strait

doi:10.1016/j.jnucmat.2006.12.046

Initial results of H-mode edge pedestal turbulence evolution with quadrature reflectometer measurements on DIII-D

G. Wang, W. A. Peebles, E. J. Doyle, T. L. Rhodes, L. Zeng, X. Nguyen, T. H. Osborne, P. B. Snyder, G. J. Kramer, R. Nazikian, R. J. Groebner, K. H. Burrell, A. W. Leonard, M. E. Fenstermacher, E. J. Strait

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Abstract

High-resolution quadrature reflectometer measurements of density fluctuation levels have been obtained on DIII-D for H-mode edge pedestal studies. Initial results are presented from the L-H transition to the first ELM for two cases: (i) a low pedestal beta discharge, in which density turbulence in the pedestal has little change during the ELM-free phase, and (ii) a high pedestal beta discharge in which both density and magnetic turbulence are observed to increase before the first ELM. These high beta data are consistent with the existence of electromagnetic turbulence suggested by some transport models. During Type-I ELM cycles, when little magnetic turbulence can be observed, pedestal turbulence increases just after an ELM crash and then decreases before next ELM strikes, in contrast to a drop after ELM crash and then it re-grows when strong magnetic turbulence shows similar behavior. Clear ELM precursors are observed on ≤20% of Type-I ELMs observed to date.

Original language	English (US)
Pages (from-to)	534-538
Number of pages	5
Journal	Journal of Nuclear Materials
Volume	363-365
Issue number	1-3
DOIs	https://doi.org/10.1016/j.jnucmat.2006.12.046
State	Published - Jun 15 2007

All Science Journal Classification (ASJC) codes

Nuclear and High Energy Physics
General Materials Science
Nuclear Energy and Engineering

Keywords

DIII-D
Edge pedestal
Edge plasma
ELM
Fluctuations and turbulence
P0500
P0600

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10.1016/j.jnucmat.2006.12.046

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Wang, G., Peebles, W. A., Doyle, E. J., Rhodes, T. L., Zeng, L., Nguyen, X., Osborne, T. H., Snyder, P. B., Kramer, G. J., Nazikian, R., Groebner, R. J., Burrell, K. H., Leonard, A. W., Fenstermacher, M. E., & Strait, E. J. (2007). Initial results of H-mode edge pedestal turbulence evolution with quadrature reflectometer measurements on DIII-D. Journal of Nuclear Materials, 363-365(1-3), 534-538. https://doi.org/10.1016/j.jnucmat.2006.12.046

@article{74cd1ecff14e46c28fadd26d61fa34d4,

title = "Initial results of H-mode edge pedestal turbulence evolution with quadrature reflectometer measurements on DIII-D",

abstract = "High-resolution quadrature reflectometer measurements of density fluctuation levels have been obtained on DIII-D for H-mode edge pedestal studies. Initial results are presented from the L-H transition to the first ELM for two cases: (i) a low pedestal beta discharge, in which density turbulence in the pedestal has little change during the ELM-free phase, and (ii) a high pedestal beta discharge in which both density and magnetic turbulence are observed to increase before the first ELM. These high beta data are consistent with the existence of electromagnetic turbulence suggested by some transport models. During Type-I ELM cycles, when little magnetic turbulence can be observed, pedestal turbulence increases just after an ELM crash and then decreases before next ELM strikes, in contrast to a drop after ELM crash and then it re-grows when strong magnetic turbulence shows similar behavior. Clear ELM precursors are observed on ≤20\% of Type-I ELMs observed to date.",

keywords = "DIII-D, Edge pedestal, Edge plasma, ELM, Fluctuations and turbulence, P0500, P0600",

author = "G. Wang and Peebles, \{W. A.\} and Doyle, \{E. J.\} and Rhodes, \{T. L.\} and L. Zeng and X. Nguyen and Osborne, \{T. H.\} and Snyder, \{P. B.\} and Kramer, \{G. J.\} and R. Nazikian and Groebner, \{R. J.\} and Burrell, \{K. H.\} and Leonard, \{A. W.\} and Fenstermacher, \{M. E.\} and Strait, \{E. J.\}",

year = "2007",

month = jun,

day = "15",

doi = "10.1016/j.jnucmat.2006.12.046",

language = "English (US)",

volume = "363-365",

pages = "534--538",

journal = "Journal of Nuclear Materials",

issn = "0022-3115",

publisher = "Elsevier B.V.",

number = "1-3",

}

Wang, G, Peebles, WA, Doyle, EJ, Rhodes, TL, Zeng, L, Nguyen, X, Osborne, TH, Snyder, PB, Kramer, GJ, Nazikian, R, Groebner, RJ, Burrell, KH, Leonard, AW, Fenstermacher, ME & Strait, EJ 2007, 'Initial results of H-mode edge pedestal turbulence evolution with quadrature reflectometer measurements on DIII-D', Journal of Nuclear Materials, vol. 363-365, no. 1-3, pp. 534-538. https://doi.org/10.1016/j.jnucmat.2006.12.046

TY - JOUR

T1 - Initial results of H-mode edge pedestal turbulence evolution with quadrature reflectometer measurements on DIII-D

AU - Wang, G.

AU - Peebles, W. A.

AU - Doyle, E. J.

AU - Rhodes, T. L.

AU - Zeng, L.

AU - Nguyen, X.

AU - Osborne, T. H.

AU - Snyder, P. B.

AU - Kramer, G. J.

AU - Nazikian, R.

AU - Groebner, R. J.

AU - Burrell, K. H.

AU - Leonard, A. W.

AU - Fenstermacher, M. E.

AU - Strait, E. J.

PY - 2007/6/15

Y1 - 2007/6/15

N2 - High-resolution quadrature reflectometer measurements of density fluctuation levels have been obtained on DIII-D for H-mode edge pedestal studies. Initial results are presented from the L-H transition to the first ELM for two cases: (i) a low pedestal beta discharge, in which density turbulence in the pedestal has little change during the ELM-free phase, and (ii) a high pedestal beta discharge in which both density and magnetic turbulence are observed to increase before the first ELM. These high beta data are consistent with the existence of electromagnetic turbulence suggested by some transport models. During Type-I ELM cycles, when little magnetic turbulence can be observed, pedestal turbulence increases just after an ELM crash and then decreases before next ELM strikes, in contrast to a drop after ELM crash and then it re-grows when strong magnetic turbulence shows similar behavior. Clear ELM precursors are observed on ≤20% of Type-I ELMs observed to date.

AB - High-resolution quadrature reflectometer measurements of density fluctuation levels have been obtained on DIII-D for H-mode edge pedestal studies. Initial results are presented from the L-H transition to the first ELM for two cases: (i) a low pedestal beta discharge, in which density turbulence in the pedestal has little change during the ELM-free phase, and (ii) a high pedestal beta discharge in which both density and magnetic turbulence are observed to increase before the first ELM. These high beta data are consistent with the existence of electromagnetic turbulence suggested by some transport models. During Type-I ELM cycles, when little magnetic turbulence can be observed, pedestal turbulence increases just after an ELM crash and then decreases before next ELM strikes, in contrast to a drop after ELM crash and then it re-grows when strong magnetic turbulence shows similar behavior. Clear ELM precursors are observed on ≤20% of Type-I ELMs observed to date.

KW - DIII-D

KW - Edge pedestal

KW - Edge plasma

KW - ELM

KW - Fluctuations and turbulence

KW - P0500

KW - P0600

UR - https://www.scopus.com/pages/publications/34248512766

UR - https://www.scopus.com/inward/citedby.url?scp=34248512766&partnerID=8YFLogxK

U2 - 10.1016/j.jnucmat.2006.12.046

DO - 10.1016/j.jnucmat.2006.12.046

M3 - Article

AN - SCOPUS:34248512766

SN - 0022-3115

VL - 363-365

SP - 534

EP - 538

JO - Journal of Nuclear Materials

JF - Journal of Nuclear Materials

IS - 1-3

ER -

Initial results of H-mode edge pedestal turbulence evolution with quadrature reflectometer measurements on DIII-D

Abstract

All Science Journal Classification (ASJC) codes

Keywords

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