Progress toward fully noninductive discharge operation in DIII-D using off-axis neutral beam injection

J. R. Ferron; C. T. Holcomb; T. C. Luce; J. M. Park; P. A. Politzer; F. Turco; W. W. Heidbrink; E. J. Doyle; J. M. Hanson; A. W. Hyatt; Y. In; R. J. La Haye; M. J. Lanctot; M. Okabayashi; T. W. Petrie; C. C. Petty; L. Zeng

doi:10.1063/1.4821072

Progress toward fully noninductive discharge operation in DIII-D using off-axis neutral beam injection

J. R. Ferron
, C. T. Holcomb
, T. C. Luce
, J. M. Park
, P. A. Politzer
, F. Turco
, W. W. Heidbrink
, E. J. Doyle
, J. M. Hanson
, A. W. Hyatt
, Y. In
, R. J. La Haye
, M. J. Lanctot
, M. Okabayashi
, T. W. Petrie
, C. C. Petty
, L. Zeng

Fusion Theory and Modeling

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

21 Scopus citations

Abstract

The initial experiments on off-axis neutral beam injection into high noninductive current fraction (f NI), high normalized pressure (β N) discharges in DIII-D [J. L. Luxon, Fusion Sci. Technol. 48, 828 (2005)] have demonstrated changes in the plasma profiles that increase the limits to plasma pressure from ideal low-n instabilities. The current profile is broadened and the minimum value of the safety factor (q min) can be maintained above 2 where the profile of the thermal component of the plasma pressure is found to be broader. The off-axis neutral beam injection results in a broadening of the fast-ion pressure profile. Confinement of the thermal component of the plasma is consistent with the IPB98(y,2) scaling, but global confinement with q min > 2 is below the ITER-89P scaling, apparently as a result of enhanced transport of fast ions. A 0-D model is used to examine the parameter space for f NI = 1 operation and project the requirements for high performance steady-state discharges. Fully noninductive solutions are found with 4 < β N < 5 and bootstrap current fraction near 0.5 for a weak shear safety factor profile. A 1-D model is used to show that a f NI = 1 discharge at the top of this range of β N that is predicted stable to n = 1, 2, and 3 ideal MHD instabilities is accessible through further broadening of the current and pressure profiles with off-axis neutral beam injection and electron cyclotron current drive.

Original language	English
Article number	092504
Journal	Physics of Plasmas
Volume	20
Issue number	9
DOIs	https://doi.org/10.1063/1.4821072
State	Published - Sep 2013

Funding

This work was supported in part by the US Department of Energy under DE-FC02-04ER54698, DE-AC52-07NA27344, DE-AC05-00OR22725, DE-FG02-04ER54761, SC-G903402, DE-FG02-08ER54984, DE-FG02-06ER84442, and DE-AC02-09CH11466.

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10.1063/1.4821072

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Ferron, J. R., Holcomb, C. T., Luce, T. C., Park, J. M., Politzer, P. A., Turco, F., Heidbrink, W. W., Doyle, E. J., Hanson, J. M., Hyatt, A. W., In, Y., La Haye, R. J., Lanctot, M. J., Okabayashi, M., Petrie, T. W., Petty, C. C., & Zeng, L. (2013). Progress toward fully noninductive discharge operation in DIII-D using off-axis neutral beam injection. Physics of Plasmas, 20(9), Article 092504. https://doi.org/10.1063/1.4821072

@article{3e383e50a2df4696b9e58ca32b2f9b20,

title = "Progress toward fully noninductive discharge operation in DIII-D using off-axis neutral beam injection",

abstract = "The initial experiments on off-axis neutral beam injection into high noninductive current fraction (f NI), high normalized pressure (β N) discharges in DIII-D [J. L. Luxon, Fusion Sci. Technol. 48, 828 (2005)] have demonstrated changes in the plasma profiles that increase the limits to plasma pressure from ideal low-n instabilities. The current profile is broadened and the minimum value of the safety factor (q min) can be maintained above 2 where the profile of the thermal component of the plasma pressure is found to be broader. The off-axis neutral beam injection results in a broadening of the fast-ion pressure profile. Confinement of the thermal component of the plasma is consistent with the IPB98(y,2) scaling, but global confinement with q min > 2 is below the ITER-89P scaling, apparently as a result of enhanced transport of fast ions. A 0-D model is used to examine the parameter space for f NI = 1 operation and project the requirements for high performance steady-state discharges. Fully noninductive solutions are found with 4 < β N < 5 and bootstrap current fraction near 0.5 for a weak shear safety factor profile. A 1-D model is used to show that a f NI = 1 discharge at the top of this range of β N that is predicted stable to n = 1, 2, and 3 ideal MHD instabilities is accessible through further broadening of the current and pressure profiles with off-axis neutral beam injection and electron cyclotron current drive.",

author = "Ferron, \{J. R.\} and Holcomb, \{C. T.\} and Luce, \{T. C.\} and Park, \{J. M.\} and Politzer, \{P. A.\} and F. Turco and Heidbrink, \{W. W.\} and Doyle, \{E. J.\} and Hanson, \{J. M.\} and Hyatt, \{A. W.\} and Y. In and \{La Haye\}, \{R. J.\} and Lanctot, \{M. J.\} and M. Okabayashi and Petrie, \{T. W.\} and Petty, \{C. C.\} and L. Zeng",

year = "2013",

month = sep,

doi = "10.1063/1.4821072",

language = "English",

volume = "20",

journal = "Physics of Plasmas",

issn = "1070-664X",

publisher = "American Institute of Physics",

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Ferron, JR, Holcomb, CT, Luce, TC, Park, JM, Politzer, PA, Turco, F, Heidbrink, WW, Doyle, EJ, Hanson, JM, Hyatt, AW, In, Y, La Haye, RJ, Lanctot, MJ, Okabayashi, M, Petrie, TW, Petty, CC & Zeng, L 2013, 'Progress toward fully noninductive discharge operation in DIII-D using off-axis neutral beam injection', Physics of Plasmas, vol. 20, no. 9, 092504. https://doi.org/10.1063/1.4821072

TY - JOUR

T1 - Progress toward fully noninductive discharge operation in DIII-D using off-axis neutral beam injection

AU - Ferron, J. R.

AU - Holcomb, C. T.

AU - Luce, T. C.

AU - Park, J. M.

AU - Politzer, P. A.

AU - Turco, F.

AU - Heidbrink, W. W.

AU - Doyle, E. J.

AU - Hanson, J. M.

AU - Hyatt, A. W.

AU - In, Y.

AU - La Haye, R. J.

AU - Lanctot, M. J.

AU - Okabayashi, M.

AU - Petrie, T. W.

AU - Petty, C. C.

AU - Zeng, L.

PY - 2013/9

Y1 - 2013/9

N2 - The initial experiments on off-axis neutral beam injection into high noninductive current fraction (f NI), high normalized pressure (β N) discharges in DIII-D [J. L. Luxon, Fusion Sci. Technol. 48, 828 (2005)] have demonstrated changes in the plasma profiles that increase the limits to plasma pressure from ideal low-n instabilities. The current profile is broadened and the minimum value of the safety factor (q min) can be maintained above 2 where the profile of the thermal component of the plasma pressure is found to be broader. The off-axis neutral beam injection results in a broadening of the fast-ion pressure profile. Confinement of the thermal component of the plasma is consistent with the IPB98(y,2) scaling, but global confinement with q min > 2 is below the ITER-89P scaling, apparently as a result of enhanced transport of fast ions. A 0-D model is used to examine the parameter space for f NI = 1 operation and project the requirements for high performance steady-state discharges. Fully noninductive solutions are found with 4 < β N < 5 and bootstrap current fraction near 0.5 for a weak shear safety factor profile. A 1-D model is used to show that a f NI = 1 discharge at the top of this range of β N that is predicted stable to n = 1, 2, and 3 ideal MHD instabilities is accessible through further broadening of the current and pressure profiles with off-axis neutral beam injection and electron cyclotron current drive.

AB - The initial experiments on off-axis neutral beam injection into high noninductive current fraction (f NI), high normalized pressure (β N) discharges in DIII-D [J. L. Luxon, Fusion Sci. Technol. 48, 828 (2005)] have demonstrated changes in the plasma profiles that increase the limits to plasma pressure from ideal low-n instabilities. The current profile is broadened and the minimum value of the safety factor (q min) can be maintained above 2 where the profile of the thermal component of the plasma pressure is found to be broader. The off-axis neutral beam injection results in a broadening of the fast-ion pressure profile. Confinement of the thermal component of the plasma is consistent with the IPB98(y,2) scaling, but global confinement with q min > 2 is below the ITER-89P scaling, apparently as a result of enhanced transport of fast ions. A 0-D model is used to examine the parameter space for f NI = 1 operation and project the requirements for high performance steady-state discharges. Fully noninductive solutions are found with 4 < β N < 5 and bootstrap current fraction near 0.5 for a weak shear safety factor profile. A 1-D model is used to show that a f NI = 1 discharge at the top of this range of β N that is predicted stable to n = 1, 2, and 3 ideal MHD instabilities is accessible through further broadening of the current and pressure profiles with off-axis neutral beam injection and electron cyclotron current drive.

UR - https://www.scopus.com/pages/publications/84885067065

U2 - 10.1063/1.4821072

DO - 10.1063/1.4821072

M3 - Article

AN - SCOPUS:84885067065

SN - 1070-664X

VL - 20

JO - Physics of Plasmas

JF - Physics of Plasmas

IS - 9

M1 - 092504

ER -

Progress toward fully noninductive discharge operation in DIII-D using off-axis neutral beam injection

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