Pedestal profiles and fluctuations in C-Mod enhanced D-alpha H-modes

A. E. Hubbard; R. L. Boivin; R. S. Granetz; M. Greenwald; J. W. Hughes; I. H. Hutchinson; J. Irby; B. LaBombard; Y. Lin; E. S. Marmar; A. Mazurenko; D. Mossessian; E. Nelson-Melby; M. Porkolab; J. A. Snipes; J. Terry; S. Wolfe; S. Wukitch; B. A. Carreras; V. Klein; T. Sunn Pedersen

doi:10.1063/1.1348329

Pedestal profiles and fluctuations in C-Mod enhanced D-alpha H-modes

A. E. Hubbard
, R. L. Boivin
, R. S. Granetz
, M. Greenwald
, J. W. Hughes
, I. H. Hutchinson
, J. Irby
, B. LaBombard
, Y. Lin
, E. S. Marmar
, A. Mazurenko
, D. Mossessian
, E. Nelson-Melby
, M. Porkolab
, J. A. Snipes
, J. Terry
, S. Wolfe
, S. Wukitch
, B. A. Carreras
, V. Klein

T. Sunn Pedersen

Research output: Contribution to journal › Conference article › peer-review

91 Scopus citations

Abstract

High resolution measurements on the Alcator C-Mod tokamak [I. H. Hutchinson et al., Phys. Plasmas 1, 1551 (1994)] of the transport barrier in the "Enhanced D_α" (EDA) regime, which has increased particle transport without large edge localized modes, show steep density and temperature gradients over a region of 2-5 mm, with peak pressure gradients up to 12 MPa/m, Evolution of the pedestal at the L-H transition is consistent with a large, rapid drop in thermal conductivity across the barrier. A quasi-coherent fluctuation in density, potential, and B_pol, with f₀ ∼ 50 - 150 kHz and k_θ ∼ 4 cm^-1, always appears in the barrier during EDA, and drives a large particle flux. Conditions to access the steady-state EDA regime in deuterium include δ>0.35, q₉₅>3.5, and L-mode target density n̄_e>1.2X10²⁰m^-3. A reduced q₉₅ limit is found for hydrogen discharges.

Original language	English (US)
Pages (from-to)	2033-2040
Number of pages	8
Journal	Physics of Plasmas
Volume	8
Issue number	5 II
DOIs	https://doi.org/10.1063/1.1348329
State	Published - May 2001
Externally published	Yes
Event	42nd Annual Meeting of the APS Division of Plasma Physics - Quebec, Que, Canada Duration: Oct 23 2000 → Oct 27 2000

All Science Journal Classification (ASJC) codes

Condensed Matter Physics

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10.1063/1.1348329

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Hubbard, A. E., Boivin, R. L., Granetz, R. S., Greenwald, M., Hughes, J. W., Hutchinson, I. H., Irby, J., LaBombard, B., Lin, Y., Marmar, E. S., Mazurenko, A., Mossessian, D., Nelson-Melby, E., Porkolab, M., Snipes, J. A., Terry, J., Wolfe, S., Wukitch, S., Carreras, B. A., ... Sunn Pedersen, T. (2001). Pedestal profiles and fluctuations in C-Mod enhanced D-alpha H-modes. Physics of Plasmas, 8(5 II), 2033-2040. https://doi.org/10.1063/1.1348329

@article{61765320c81b4a0cb1be24a451a563d9,

title = "Pedestal profiles and fluctuations in C-Mod enhanced D-alpha H-modes",

abstract = "High resolution measurements on the Alcator C-Mod tokamak [I. H. Hutchinson et al., Phys. Plasmas 1, 1551 (1994)] of the transport barrier in the {"}Enhanced Dα{"} (EDA) regime, which has increased particle transport without large edge localized modes, show steep density and temperature gradients over a region of 2-5 mm, with peak pressure gradients up to 12 MPa/m, Evolution of the pedestal at the L-H transition is consistent with a large, rapid drop in thermal conductivity across the barrier. A quasi-coherent fluctuation in density, potential, and Bpol, with f0 ∼ 50 - 150 kHz and kθ ∼ 4 cm-1, always appears in the barrier during EDA, and drives a large particle flux. Conditions to access the steady-state EDA regime in deuterium include δ>0.35, q95>3.5, and L-mode target density {\=n}e>1.2X1020m-3. A reduced q95 limit is found for hydrogen discharges.",

author = "Hubbard, \{A. E.\} and Boivin, \{R. L.\} and Granetz, \{R. S.\} and M. Greenwald and Hughes, \{J. W.\} and Hutchinson, \{I. H.\} and J. Irby and B. LaBombard and Y. Lin and Marmar, \{E. S.\} and A. Mazurenko and D. Mossessian and E. Nelson-Melby and M. Porkolab and Snipes, \{J. A.\} and J. Terry and S. Wolfe and S. Wukitch and Carreras, \{B. A.\} and V. Klein and \{Sunn Pedersen\}, T.",

year = "2001",

month = may,

doi = "10.1063/1.1348329",

language = "English (US)",

volume = "8",

pages = "2033--2040",

journal = "Physics of Plasmas",

issn = "1070-664X",

publisher = "American Institute of Physics",

number = "5 II",

note = "42nd Annual Meeting of the APS Division of Plasma Physics ; Conference date: 23-10-2000 Through 27-10-2000",

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Hubbard, AE, Boivin, RL, Granetz, RS, Greenwald, M, Hughes, JW, Hutchinson, IH, Irby, J, LaBombard, B, Lin, Y, Marmar, ES, Mazurenko, A, Mossessian, D, Nelson-Melby, E, Porkolab, M, Snipes, JA, Terry, J, Wolfe, S, Wukitch, S, Carreras, BA, Klein, V & Sunn Pedersen, T 2001, 'Pedestal profiles and fluctuations in C-Mod enhanced D-alpha H-modes', Physics of Plasmas, vol. 8, no. 5 II, pp. 2033-2040. https://doi.org/10.1063/1.1348329

TY - JOUR

T1 - Pedestal profiles and fluctuations in C-Mod enhanced D-alpha H-modes

AU - Hubbard, A. E.

AU - Boivin, R. L.

AU - Granetz, R. S.

AU - Greenwald, M.

AU - Hughes, J. W.

AU - Hutchinson, I. H.

AU - Irby, J.

AU - LaBombard, B.

AU - Lin, Y.

AU - Marmar, E. S.

AU - Mazurenko, A.

AU - Mossessian, D.

AU - Nelson-Melby, E.

AU - Porkolab, M.

AU - Snipes, J. A.

AU - Terry, J.

AU - Wolfe, S.

AU - Wukitch, S.

AU - Carreras, B. A.

AU - Klein, V.

AU - Sunn Pedersen, T.

PY - 2001/5

Y1 - 2001/5

N2 - High resolution measurements on the Alcator C-Mod tokamak [I. H. Hutchinson et al., Phys. Plasmas 1, 1551 (1994)] of the transport barrier in the "Enhanced Dα" (EDA) regime, which has increased particle transport without large edge localized modes, show steep density and temperature gradients over a region of 2-5 mm, with peak pressure gradients up to 12 MPa/m, Evolution of the pedestal at the L-H transition is consistent with a large, rapid drop in thermal conductivity across the barrier. A quasi-coherent fluctuation in density, potential, and Bpol, with f0 ∼ 50 - 150 kHz and kθ ∼ 4 cm-1, always appears in the barrier during EDA, and drives a large particle flux. Conditions to access the steady-state EDA regime in deuterium include δ>0.35, q95>3.5, and L-mode target density n̄e>1.2X1020m-3. A reduced q95 limit is found for hydrogen discharges.

AB - High resolution measurements on the Alcator C-Mod tokamak [I. H. Hutchinson et al., Phys. Plasmas 1, 1551 (1994)] of the transport barrier in the "Enhanced Dα" (EDA) regime, which has increased particle transport without large edge localized modes, show steep density and temperature gradients over a region of 2-5 mm, with peak pressure gradients up to 12 MPa/m, Evolution of the pedestal at the L-H transition is consistent with a large, rapid drop in thermal conductivity across the barrier. A quasi-coherent fluctuation in density, potential, and Bpol, with f0 ∼ 50 - 150 kHz and kθ ∼ 4 cm-1, always appears in the barrier during EDA, and drives a large particle flux. Conditions to access the steady-state EDA regime in deuterium include δ>0.35, q95>3.5, and L-mode target density n̄e>1.2X1020m-3. A reduced q95 limit is found for hydrogen discharges.

UR - https://www.scopus.com/pages/publications/6644225237

UR - https://www.scopus.com/pages/publications/6644225237#tab=citedBy

U2 - 10.1063/1.1348329

DO - 10.1063/1.1348329

M3 - Conference article

AN - SCOPUS:6644225237

SN - 1070-664X

VL - 8

SP - 2033

EP - 2040

JO - Physics of Plasmas

JF - Physics of Plasmas

IS - 5 II

T2 - 42nd Annual Meeting of the APS Division of Plasma Physics

Y2 - 23 October 2000 through 27 October 2000

ER -

Pedestal profiles and fluctuations in C-Mod enhanced D-alpha H-modes

Abstract

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