Some effects of MHD activity on impurity transport in the PBX Tokamak

K. Ida; R. J. Fonck; R. A. Hulse; B. Leblanc

doi:10.1088/0741-3335/28/6/004

Some effects of MHD activity on impurity transport in the PBX Tokamak

K. Ida
, R. J. Fonck
, R. A. Hulse
, B. Leblanc

PPPL NSTX

Research output: Contribution to journal › Article › peer-review

24 Scopus citations

Abstract

The effects of MHD activity on intrinsic impurity transport are studied in ohmic discharges of the Princeton Beta Experiment (PBX) by measuring the Z _eff profile from visible bremsstrahlung radiation and spectral line intensities from ultraviolet spectroscopy. A diffusive/convective transport model, including an internal disruption model, is used to simulate the data. The Z_eff profile with no MHD activity is fitted with a strong inward convection, characterized by a peaking parameter c_v(=-a² nu /2rD)=11 (-3.5, +4.5). At the onset of MHD activity (a large m=1 n=1 oscillation is followed by sawteeth), this strongly peaked profile is flattened and subsequently reaches a new quasi-equilibrium shape. This new profile is characterized by reduced convection (c_v=3.6 (-1.1, +1.6), D=1.4 (-0.7, +5.6)*10⁴ cm² s^-1) in addition to the particle redistribution which accompanies the sawtooth internal disruptions, indicating that the transport processes themselves change with the onset of sawtooth activity.

Original language	English (US)
Article number	004
Pages (from-to)	879-895
Number of pages	17
Journal	Plasma Physics and Controlled Fusion
Volume	28
Issue number	6
DOIs	https://doi.org/10.1088/0741-3335/28/6/004
State	Published - 1986

All Science Journal Classification (ASJC) codes

Nuclear Energy and Engineering
Condensed Matter Physics

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10.1088/0741-3335/28/6/004

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title = "Some effects of MHD activity on impurity transport in the PBX Tokamak",

abstract = "The effects of MHD activity on intrinsic impurity transport are studied in ohmic discharges of the Princeton Beta Experiment (PBX) by measuring the Z eff profile from visible bremsstrahlung radiation and spectral line intensities from ultraviolet spectroscopy. A diffusive/convective transport model, including an internal disruption model, is used to simulate the data. The Zeff profile with no MHD activity is fitted with a strong inward convection, characterized by a peaking parameter cv(=-a2 nu /2rD)=11 (-3.5, +4.5). At the onset of MHD activity (a large m=1 n=1 oscillation is followed by sawteeth), this strongly peaked profile is flattened and subsequently reaches a new quasi-equilibrium shape. This new profile is characterized by reduced convection (cv=3.6 (-1.1, +1.6), D=1.4 (-0.7, +5.6)*104 cm2 s-1) in addition to the particle redistribution which accompanies the sawtooth internal disruptions, indicating that the transport processes themselves change with the onset of sawtooth activity.",

author = "K. Ida and Fonck, \{R. J.\} and Hulse, \{R. A.\} and B. Leblanc",

year = "1986",

doi = "10.1088/0741-3335/28/6/004",

language = "English (US)",

volume = "28",

pages = "879--895",

journal = "Plasma Physics and Controlled Fusion",

issn = "0741-3335",

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TY - JOUR

T1 - Some effects of MHD activity on impurity transport in the PBX Tokamak

AU - Ida, K.

AU - Fonck, R. J.

AU - Hulse, R. A.

AU - Leblanc, B.

PY - 1986

Y1 - 1986

N2 - The effects of MHD activity on intrinsic impurity transport are studied in ohmic discharges of the Princeton Beta Experiment (PBX) by measuring the Z eff profile from visible bremsstrahlung radiation and spectral line intensities from ultraviolet spectroscopy. A diffusive/convective transport model, including an internal disruption model, is used to simulate the data. The Zeff profile with no MHD activity is fitted with a strong inward convection, characterized by a peaking parameter cv(=-a2 nu /2rD)=11 (-3.5, +4.5). At the onset of MHD activity (a large m=1 n=1 oscillation is followed by sawteeth), this strongly peaked profile is flattened and subsequently reaches a new quasi-equilibrium shape. This new profile is characterized by reduced convection (cv=3.6 (-1.1, +1.6), D=1.4 (-0.7, +5.6)*104 cm2 s-1) in addition to the particle redistribution which accompanies the sawtooth internal disruptions, indicating that the transport processes themselves change with the onset of sawtooth activity.

AB - The effects of MHD activity on intrinsic impurity transport are studied in ohmic discharges of the Princeton Beta Experiment (PBX) by measuring the Z eff profile from visible bremsstrahlung radiation and spectral line intensities from ultraviolet spectroscopy. A diffusive/convective transport model, including an internal disruption model, is used to simulate the data. The Zeff profile with no MHD activity is fitted with a strong inward convection, characterized by a peaking parameter cv(=-a2 nu /2rD)=11 (-3.5, +4.5). At the onset of MHD activity (a large m=1 n=1 oscillation is followed by sawteeth), this strongly peaked profile is flattened and subsequently reaches a new quasi-equilibrium shape. This new profile is characterized by reduced convection (cv=3.6 (-1.1, +1.6), D=1.4 (-0.7, +5.6)*104 cm2 s-1) in addition to the particle redistribution which accompanies the sawtooth internal disruptions, indicating that the transport processes themselves change with the onset of sawtooth activity.

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UR - https://www.scopus.com/pages/publications/0011931339#tab=citedBy

U2 - 10.1088/0741-3335/28/6/004

DO - 10.1088/0741-3335/28/6/004

M3 - Article

AN - SCOPUS:0011931339

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VL - 28

SP - 879

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JO - Plasma Physics and Controlled Fusion

JF - Plasma Physics and Controlled Fusion

IS - 6

M1 - 004

ER -

Some effects of MHD activity on impurity transport in the PBX Tokamak

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