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. KleinT. Sunn Pedersen

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

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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/inward/citedby.url?scp=6644225237&partnerID=8YFLogxK

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

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