Radiofrequency-heated enhanced confinement modes in the Alcator C-Mod tokamak

Y. Takase; R. L. Boivin; F. Bombarda; P. T. Bonoli; C. Christensen; C. Fiore; D. Garnier; J. A. Goetz; S. N. Golovato; R. Granetz; M. Greenwald; S. F. Horne; A. Hubbard; I. H. Hutchinson; J. Irby; B. Labombard; B. Lipschultz; E. Marmar; M. May; A. Mazurenko; G. Mccracken; P. O'shea; M. Porkolab; J. Reardon; J. Rice; C. Rost; J. Schachter; J. A. Snipes; P. Stek; J. Terry; R. Watterson; B. Welch; S. Wolfe

doi:10.1063/1.872269

Radiofrequency-heated enhanced confinement modes in the Alcator C-Mod tokamak

Y. Takase, R. L. Boivin, F. Bombarda, P. T. Bonoli, C. Christensen, C. Fiore, D. Garnier, J. A. Goetz, S. N. Golovato, R. Granetz, M. Greenwald, S. F. Horne, A. Hubbard, I. H. Hutchinson, J. Irby, B. Labombard, B. Lipschultz, E. Marmar, M. May, A. MazurenkoG. Mccracken, P. O'shea, M. Porkolab, J. Reardon, J. Rice, C. Rost, J. Schachter, J. A. Snipes, P. Stek, J. Terry, R. Watterson, B. Welch, S. Wolfe

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Abstract

Enhanced confinement modes up to a toroidal field of [formula omitted]T have been studied with up to 3.5 MW of radiofrequency (rf) heating power in the ion cyclotron range of frequencies (ICRF) at 80 MHz. H-mode is observed when the edge temperature exceeds a threshold value. The high confinement mode (H-mode) with higher confinement enhancement factors [formula omitted] and longer duration became possible after boronization by reducing the radiated power from the main plasma. A quasi-steady state with high confinement [formula omitted], high normalized beta [formula omitted], low radiated power fraction [formula omitted], and low effective charge [formula omitted] has been obtained in Enhanced D[formula omitted] H-mode. This type of H-mode has enhanced levels of continuous D[formula omitted] emission and very little or no edge localized mode (ELM) activity, and reduced core particle confinement time relative to ELM-free H-mode. The pellet enhanced performance (PEP) mode is obtained by combining core fueling with pellet injection and core heating. A highly peaked pressure profile with a central value of 8 atmospheres was observed. The steep pressure gradient drives off-axis bootstrap current, resulting in a shear reversed safety factor [formula omitted] profile. Suppression of sawteeth appears to be important in maintaining the highly peaked pressure profile. Lithium pellets were found to be more effective than deuterium pellets in raising [formula omitted].

Original language	English (US)
Pages (from-to)	1647-1653
Number of pages	7
Journal	Physics of Plasmas
Volume	4
Issue number	5
DOIs	https://doi.org/10.1063/1.872269
State	Published - May 1997
Externally published	Yes

All Science Journal Classification (ASJC) codes

Condensed Matter Physics

Keywords

ALCATOR DEVICE
BETA RATIO
EFFECTIVE CHARGE
H-MODE PLASMA CONFINEMENT
ICR HEATING
LITHIUM
MAGNETIC CONFINEMENT
PELLET INJECTION
SAWTOOTH OSCILLATIONS
TOROIDAL CONFIGURATION

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10.1063/1.872269

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Takase, Y., Boivin, R. L., Bombarda, F., Bonoli, P. T., Christensen, C., Fiore, C., Garnier, D., Goetz, J. A., Golovato, S. N., Granetz, R., Greenwald, M., Horne, S. F., Hubbard, A., Hutchinson, I. H., Irby, J., Labombard, B., Lipschultz, B., Marmar, E., May, M., ... Wolfe, S. (1997). Radiofrequency-heated enhanced confinement modes in the Alcator C-Mod tokamak. Physics of Plasmas, 4(5), 1647-1653. https://doi.org/10.1063/1.872269

@article{110c26e7ae8e43459f1879a9c965f906,

title = "Radiofrequency-heated enhanced confinement modes in the Alcator C-Mod tokamak",

abstract = "Enhanced confinement modes up to a toroidal field of [formula omitted]T have been studied with up to 3.5 MW of radiofrequency (rf) heating power in the ion cyclotron range of frequencies (ICRF) at 80 MHz. H-mode is observed when the edge temperature exceeds a threshold value. The high confinement mode (H-mode) with higher confinement enhancement factors [formula omitted] and longer duration became possible after boronization by reducing the radiated power from the main plasma. A quasi-steady state with high confinement [formula omitted], high normalized beta [formula omitted], low radiated power fraction [formula omitted], and low effective charge [formula omitted] has been obtained in Enhanced D[formula omitted] H-mode. This type of H-mode has enhanced levels of continuous D[formula omitted] emission and very little or no edge localized mode (ELM) activity, and reduced core particle confinement time relative to ELM-free H-mode. The pellet enhanced performance (PEP) mode is obtained by combining core fueling with pellet injection and core heating. A highly peaked pressure profile with a central value of 8 atmospheres was observed. The steep pressure gradient drives off-axis bootstrap current, resulting in a shear reversed safety factor [formula omitted] profile. Suppression of sawteeth appears to be important in maintaining the highly peaked pressure profile. Lithium pellets were found to be more effective than deuterium pellets in raising [formula omitted].",

keywords = "ALCATOR DEVICE, BETA RATIO, EFFECTIVE CHARGE, H-MODE PLASMA CONFINEMENT, ICR HEATING, LITHIUM, MAGNETIC CONFINEMENT, PELLET INJECTION, SAWTOOTH OSCILLATIONS, TOROIDAL CONFIGURATION",

author = "Y. Takase and Boivin, \{R. L.\} and F. Bombarda and Bonoli, \{P. T.\} and C. Christensen and C. Fiore and D. Garnier and Goetz, \{J. A.\} and Golovato, \{S. N.\} and R. Granetz and M. Greenwald and Horne, \{S. F.\} and A. Hubbard and Hutchinson, \{I. H.\} and J. Irby and B. Labombard and B. Lipschultz and E. Marmar and M. May and A. Mazurenko and G. Mccracken and P. O'shea and M. Porkolab and J. Reardon and J. Rice and C. Rost and J. Schachter and Snipes, \{J. A.\} and P. Stek and J. Terry and R. Watterson and B. Welch and S. Wolfe",

year = "1997",

month = may,

doi = "10.1063/1.872269",

language = "English (US)",

volume = "4",

pages = "1647--1653",

journal = "Physics of Plasmas",

issn = "1070-664X",

publisher = "American Institute of Physics",

number = "5",

}

Takase, Y, Boivin, RL, Bombarda, F, Bonoli, PT, Christensen, C, Fiore, C, Garnier, D, Goetz, JA, Golovato, SN, Granetz, R, Greenwald, M, Horne, SF, Hubbard, A, Hutchinson, IH, Irby, J, Labombard, B, Lipschultz, B, Marmar, E, May, M, Mazurenko, A, Mccracken, G, O'shea, P, Porkolab, M, Reardon, J, Rice, J, Rost, C, Schachter, J, Snipes, JA, Stek, P, Terry, J, Watterson, R, Welch, B & Wolfe, S 1997, 'Radiofrequency-heated enhanced confinement modes in the Alcator C-Mod tokamak', Physics of Plasmas, vol. 4, no. 5, pp. 1647-1653. https://doi.org/10.1063/1.872269

TY - JOUR

T1 - Radiofrequency-heated enhanced confinement modes in the Alcator C-Mod tokamak

AU - Takase, Y.

AU - Boivin, R. L.

AU - Bombarda, F.

AU - Bonoli, P. T.

AU - Christensen, C.

AU - Fiore, C.

AU - Garnier, D.

AU - Goetz, J. A.

AU - Golovato, S. N.

AU - Granetz, R.

AU - Greenwald, M.

AU - Horne, S. F.

AU - Hubbard, A.

AU - Hutchinson, I. H.

AU - Irby, J.

AU - Labombard, B.

AU - Lipschultz, B.

AU - Marmar, E.

AU - May, M.

AU - Mazurenko, A.

AU - Mccracken, G.

AU - O'shea, P.

AU - Porkolab, M.

AU - Reardon, J.

AU - Rice, J.

AU - Rost, C.

AU - Schachter, J.

AU - Snipes, J. A.

AU - Stek, P.

AU - Terry, J.

AU - Watterson, R.

AU - Welch, B.

AU - Wolfe, S.

PY - 1997/5

Y1 - 1997/5

N2 - Enhanced confinement modes up to a toroidal field of [formula omitted]T have been studied with up to 3.5 MW of radiofrequency (rf) heating power in the ion cyclotron range of frequencies (ICRF) at 80 MHz. H-mode is observed when the edge temperature exceeds a threshold value. The high confinement mode (H-mode) with higher confinement enhancement factors [formula omitted] and longer duration became possible after boronization by reducing the radiated power from the main plasma. A quasi-steady state with high confinement [formula omitted], high normalized beta [formula omitted], low radiated power fraction [formula omitted], and low effective charge [formula omitted] has been obtained in Enhanced D[formula omitted] H-mode. This type of H-mode has enhanced levels of continuous D[formula omitted] emission and very little or no edge localized mode (ELM) activity, and reduced core particle confinement time relative to ELM-free H-mode. The pellet enhanced performance (PEP) mode is obtained by combining core fueling with pellet injection and core heating. A highly peaked pressure profile with a central value of 8 atmospheres was observed. The steep pressure gradient drives off-axis bootstrap current, resulting in a shear reversed safety factor [formula omitted] profile. Suppression of sawteeth appears to be important in maintaining the highly peaked pressure profile. Lithium pellets were found to be more effective than deuterium pellets in raising [formula omitted].

AB - Enhanced confinement modes up to a toroidal field of [formula omitted]T have been studied with up to 3.5 MW of radiofrequency (rf) heating power in the ion cyclotron range of frequencies (ICRF) at 80 MHz. H-mode is observed when the edge temperature exceeds a threshold value. The high confinement mode (H-mode) with higher confinement enhancement factors [formula omitted] and longer duration became possible after boronization by reducing the radiated power from the main plasma. A quasi-steady state with high confinement [formula omitted], high normalized beta [formula omitted], low radiated power fraction [formula omitted], and low effective charge [formula omitted] has been obtained in Enhanced D[formula omitted] H-mode. This type of H-mode has enhanced levels of continuous D[formula omitted] emission and very little or no edge localized mode (ELM) activity, and reduced core particle confinement time relative to ELM-free H-mode. The pellet enhanced performance (PEP) mode is obtained by combining core fueling with pellet injection and core heating. A highly peaked pressure profile with a central value of 8 atmospheres was observed. The steep pressure gradient drives off-axis bootstrap current, resulting in a shear reversed safety factor [formula omitted] profile. Suppression of sawteeth appears to be important in maintaining the highly peaked pressure profile. Lithium pellets were found to be more effective than deuterium pellets in raising [formula omitted].

KW - ALCATOR DEVICE

KW - BETA RATIO

KW - EFFECTIVE CHARGE

KW - H-MODE PLASMA CONFINEMENT

KW - ICR HEATING

KW - LITHIUM

KW - MAGNETIC CONFINEMENT

KW - PELLET INJECTION

KW - SAWTOOTH OSCILLATIONS

KW - TOROIDAL CONFIGURATION

UR - https://www.scopus.com/pages/publications/0001182686

UR - https://www.scopus.com/inward/citedby.url?scp=0001182686&partnerID=8YFLogxK

U2 - 10.1063/1.872269

DO - 10.1063/1.872269

M3 - Article

AN - SCOPUS:0001182686

SN - 1070-664X

VL - 4

SP - 1647

EP - 1653

JO - Physics of Plasmas

JF - Physics of Plasmas

IS - 5

ER -

Radiofrequency-heated enhanced confinement modes in the Alcator C-Mod tokamak

Abstract

All Science Journal Classification (ASJC) codes

Keywords

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