Wave-particle studies in the ion cyclotron and lower hybrid ranges of frequencies in alcator C-Mod

P.T. Bonoli; R. Parker; S.J. Wukitch; Y. Lin; M. Porkolab; J.C. Wright; E. Edlund; T. Graves; L. Lin; J. Liptac; A. Parisot; A.E. Schmidt; V. Tang; W. Beck; R. Childs; M. Grimes; D. Gwinn; D. Johnson; J. Irby; A. Kanojia; P. Koert; S. Marazita; E. Marmar; D. Terry; R. Vieira; G. Wallace; J. Zaks; C.L. Fiore; R. Granetz; M. Greenwald; A.E. Hubbard; I.H. Hutchinson; B. LaBombard; B. Lipschultz; J. Rice; J.A. Snipes; J. Terry; S.M. Wolfe; S. Bernabei; C. Brunkhorse; R. Ellis; E. Fredd; N. Greenough; J. Hosea; C.C. Kung; G.D. Loesser; J. Rushinski; G. Schilling; C.K. Phillips; J.R. Wilson; R.W. Harvey

Wave-particle studies in the ion cyclotron and lower hybrid ranges of frequencies in alcator C-Mod

P.T. Bonoli, R. Parker, S.J. Wukitch, Y. Lin, M. Porkolab, J.C. Wright, E. Edlund, T. Graves, L. Lin, J. Liptac, A. Parisot, A.E. Schmidt, V. Tang, W. Beck, R. Childs, M. Grimes, D. Gwinn, D. Johnson, J. Irby, A. KanojiaP. Koert, S. Marazita, E. Marmar, D. Terry, R. Vieira, G. Wallace, J. Zaks, C.L. Fiore, R. Granetz, M. Greenwald, A.E. Hubbard, I.H. Hutchinson, B. LaBombard, B. Lipschultz, J. Rice, J.A. Snipes, J. Terry, S.M. Wolfe, S. Bernabei, C. Brunkhorse, R. Ellis, E. Fredd, N. Greenough, J. Hosea, C.C. Kung, G.D. Loesser, J. Rushinski, G. Schilling, C.K. Phillips, J.R. Wilson, R.W. Harvey

Physics

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

Abstract

This paper reviews the physics and technology of wave-particle - interaction experiments in the ion cyclotron range of frequencies (ICRF) and the lower hybrid (LH) range of frequencies (LHRF) on the Alcator C-Mod tokamak. Operation of fixed frequency (80 MHz) and tunable (40- to 80-MHz) ICRF transmitters and the associated transmission system is described. Key fabrication issues that were solved in order to operate a four-strap ICRF antenna in the compact environment of C-Mod are discussed in some detail. ICRF heating experiments utilizing the hydrogen (H) and helium-3 ( He) minority heating schemes are described, and data are presented demonstrating an overall heating efficiency of 70 to 90% for the (H) minority scheme and somewhat lower efficiency for ( He) minority heating. Mode conversion electron heating experiments in D( He), D(H), and H( He) discharges are also reported as well as simulations of these experiments using an advanced ICRF full-wave solver. Measurements of mode-converted ion cyclotron waves and ion Bernstein waves using a phase contrast imaging diagnostic are presented and compared with the predictions of a synthetic diagnostic code that utilizes wave electric fields from a full-wave solver. The physics basis of the LH current profile control program on Alcator C-Mod is also presented. Computer simulations using a two-dimensional (velocity space) Fokker Planck solver indicate that ∼200 kA of LH current can be driven in low-density H-mode discharges on C-Mod with ∼3 MW of LHRF power. It is shown that this off-axis LH current drive can be used to create discharges with nonmonotonic profiles of the current density and reversed shear. An advanced tokamak operating regime near the ideal no-wall β limit is described for C-Mod, where ∼70% of the current is driven through the bootstrap effect. The LH power is coupled to C-Mod through a waveguide launcher consisting of four rows (vertically) with 24 guides per row (toroidally). A detailed description of the LH launcher fabrication is given in this paper along with initial operation results.

Original language	English
Pages (from-to)	401-436
Number of pages	36
Journal	Fusion science and technology
Volume	51
Issue number	3
Publication status	Published - 1 Apr 2007

Cite this

Bonoli, P. T., Parker, R., Wukitch, S. J., Lin, Y., Porkolab, M., Wright, J. C., Edlund, E., Graves, T., Lin, L., Liptac, J., Parisot, A., Schmidt, A. E., Tang, V., Beck, W., Childs, R., Grimes, M., Gwinn, D., Johnson, D., Irby, J., ... Harvey, R. W. (2007). Wave-particle studies in the ion cyclotron and lower hybrid ranges of frequencies in alcator C-Mod. Fusion science and technology, 51(3), 401-436.

@article{1ab70939e83d40899d08f050ded42fc9,

title = "Wave-particle studies in the ion cyclotron and lower hybrid ranges of frequencies in alcator C-Mod",

abstract = "This paper reviews the physics and technology of wave-particle - interaction experiments in the ion cyclotron range of frequencies (ICRF) and the lower hybrid (LH) range of frequencies (LHRF) on the Alcator C-Mod tokamak. Operation of fixed frequency (80 MHz) and tunable (40- to 80-MHz) ICRF transmitters and the associated transmission system is described. Key fabrication issues that were solved in order to operate a four-strap ICRF antenna in the compact environment of C-Mod are discussed in some detail. ICRF heating experiments utilizing the hydrogen (H) and helium-3 ( He) minority heating schemes are described, and data are presented demonstrating an overall heating efficiency of 70 to 90% for the (H) minority scheme and somewhat lower efficiency for ( He) minority heating. Mode conversion electron heating experiments in D( He), D(H), and H( He) discharges are also reported as well as simulations of these experiments using an advanced ICRF full-wave solver. Measurements of mode-converted ion cyclotron waves and ion Bernstein waves using a phase contrast imaging diagnostic are presented and compared with the predictions of a synthetic diagnostic code that utilizes wave electric fields from a full-wave solver. The physics basis of the LH current profile control program on Alcator C-Mod is also presented. Computer simulations using a two-dimensional (velocity space) Fokker Planck solver indicate that ∼200 kA of LH current can be driven in low-density H-mode discharges on C-Mod with ∼3 MW of LHRF power. It is shown that this off-axis LH current drive can be used to create discharges with nonmonotonic profiles of the current density and reversed shear. An advanced tokamak operating regime near the ideal no-wall β limit is described for C-Mod, where ∼70% of the current is driven through the bootstrap effect. The LH power is coupled to C-Mod through a waveguide launcher consisting of four rows (vertically) with 24 guides per row (toroidally). A detailed description of the LH launcher fabrication is given in this paper along with initial operation results.",

author = "P.T. Bonoli and R. Parker and S.J. Wukitch and Y. Lin and M. Porkolab and J.C. Wright and E. Edlund and T. Graves and L. Lin and J. Liptac and A. Parisot and A.E. Schmidt and V. Tang and W. Beck and R. Childs and M. Grimes and D. Gwinn and D. Johnson and J. Irby and A. Kanojia and P. Koert and S. Marazita and E. Marmar and D. Terry and R. Vieira and G. Wallace and J. Zaks and C.L. Fiore and R. Granetz and M. Greenwald and A.E. Hubbard and I.H. Hutchinson and B. LaBombard and B. Lipschultz and J. Rice and J.A. Snipes and J. Terry and S.M. Wolfe and S. Bernabei and C. Brunkhorse and R. Ellis and E. Fredd and N. Greenough and J. Hosea and C.C. Kung and G.D. Loesser and J. Rushinski and G. Schilling and C.K. Phillips and J.R. Wilson and R.W. Harvey",

year = "2007",

month = apr,

day = "1",

language = "English",

volume = "51",

pages = "401--436",

journal = "Fusion science and technology",

issn = "1536-1055",

publisher = "American Nuclear Society",

number = "3",

}

Bonoli, PT, Parker, R, Wukitch, SJ, Lin, Y, Porkolab, M, Wright, JC, Edlund, E, Graves, T, Lin, L, Liptac, J, Parisot, A, Schmidt, AE, Tang, V, Beck, W, Childs, R, Grimes, M, Gwinn, D, Johnson, D, Irby, J, Kanojia, A, Koert, P, Marazita, S, Marmar, E, Terry, D, Vieira, R, Wallace, G, Zaks, J, Fiore, CL, Granetz, R, Greenwald, M, Hubbard, AE, Hutchinson, IH, LaBombard, B, Lipschultz, B, Rice, J, Snipes, JA, Terry, J, Wolfe, SM, Bernabei, S, Brunkhorse, C, Ellis, R, Fredd, E, Greenough, N, Hosea, J, Kung, CC, Loesser, GD, Rushinski, J, Schilling, G, Phillips, CK, Wilson, JR & Harvey, RW 2007, 'Wave-particle studies in the ion cyclotron and lower hybrid ranges of frequencies in alcator C-Mod', Fusion science and technology, vol. 51, no. 3, pp. 401-436.

TY - JOUR

T1 - Wave-particle studies in the ion cyclotron and lower hybrid ranges of frequencies in alcator C-Mod

AU - Bonoli, P.T.

AU - Parker, R.

AU - Wukitch, S.J.

AU - Lin, Y.

AU - Porkolab, M.

AU - Wright, J.C.

AU - Edlund, E.

AU - Graves, T.

AU - Lin, L.

AU - Liptac, J.

AU - Parisot, A.

AU - Schmidt, A.E.

AU - Tang, V.

AU - Beck, W.

AU - Childs, R.

AU - Grimes, M.

AU - Gwinn, D.

AU - Johnson, D.

AU - Irby, J.

AU - Kanojia, A.

AU - Koert, P.

AU - Marazita, S.

AU - Marmar, E.

AU - Terry, D.

AU - Vieira, R.

AU - Wallace, G.

AU - Zaks, J.

AU - Fiore, C.L.

AU - Granetz, R.

AU - Greenwald, M.

AU - Hubbard, A.E.

AU - Hutchinson, I.H.

AU - LaBombard, B.

AU - Lipschultz, B.

AU - Rice, J.

AU - Snipes, J.A.

AU - Terry, J.

AU - Wolfe, S.M.

AU - Bernabei, S.

AU - Brunkhorse, C.

AU - Ellis, R.

AU - Fredd, E.

AU - Greenough, N.

AU - Hosea, J.

AU - Kung, C.C.

AU - Loesser, G.D.

AU - Rushinski, J.

AU - Schilling, G.

AU - Phillips, C.K.

AU - Wilson, J.R.

AU - Harvey, R.W.

PY - 2007/4/1

Y1 - 2007/4/1

N2 - This paper reviews the physics and technology of wave-particle - interaction experiments in the ion cyclotron range of frequencies (ICRF) and the lower hybrid (LH) range of frequencies (LHRF) on the Alcator C-Mod tokamak. Operation of fixed frequency (80 MHz) and tunable (40- to 80-MHz) ICRF transmitters and the associated transmission system is described. Key fabrication issues that were solved in order to operate a four-strap ICRF antenna in the compact environment of C-Mod are discussed in some detail. ICRF heating experiments utilizing the hydrogen (H) and helium-3 ( He) minority heating schemes are described, and data are presented demonstrating an overall heating efficiency of 70 to 90% for the (H) minority scheme and somewhat lower efficiency for ( He) minority heating. Mode conversion electron heating experiments in D( He), D(H), and H( He) discharges are also reported as well as simulations of these experiments using an advanced ICRF full-wave solver. Measurements of mode-converted ion cyclotron waves and ion Bernstein waves using a phase contrast imaging diagnostic are presented and compared with the predictions of a synthetic diagnostic code that utilizes wave electric fields from a full-wave solver. The physics basis of the LH current profile control program on Alcator C-Mod is also presented. Computer simulations using a two-dimensional (velocity space) Fokker Planck solver indicate that ∼200 kA of LH current can be driven in low-density H-mode discharges on C-Mod with ∼3 MW of LHRF power. It is shown that this off-axis LH current drive can be used to create discharges with nonmonotonic profiles of the current density and reversed shear. An advanced tokamak operating regime near the ideal no-wall β limit is described for C-Mod, where ∼70% of the current is driven through the bootstrap effect. The LH power is coupled to C-Mod through a waveguide launcher consisting of four rows (vertically) with 24 guides per row (toroidally). A detailed description of the LH launcher fabrication is given in this paper along with initial operation results.

AB - This paper reviews the physics and technology of wave-particle - interaction experiments in the ion cyclotron range of frequencies (ICRF) and the lower hybrid (LH) range of frequencies (LHRF) on the Alcator C-Mod tokamak. Operation of fixed frequency (80 MHz) and tunable (40- to 80-MHz) ICRF transmitters and the associated transmission system is described. Key fabrication issues that were solved in order to operate a four-strap ICRF antenna in the compact environment of C-Mod are discussed in some detail. ICRF heating experiments utilizing the hydrogen (H) and helium-3 ( He) minority heating schemes are described, and data are presented demonstrating an overall heating efficiency of 70 to 90% for the (H) minority scheme and somewhat lower efficiency for ( He) minority heating. Mode conversion electron heating experiments in D( He), D(H), and H( He) discharges are also reported as well as simulations of these experiments using an advanced ICRF full-wave solver. Measurements of mode-converted ion cyclotron waves and ion Bernstein waves using a phase contrast imaging diagnostic are presented and compared with the predictions of a synthetic diagnostic code that utilizes wave electric fields from a full-wave solver. The physics basis of the LH current profile control program on Alcator C-Mod is also presented. Computer simulations using a two-dimensional (velocity space) Fokker Planck solver indicate that ∼200 kA of LH current can be driven in low-density H-mode discharges on C-Mod with ∼3 MW of LHRF power. It is shown that this off-axis LH current drive can be used to create discharges with nonmonotonic profiles of the current density and reversed shear. An advanced tokamak operating regime near the ideal no-wall β limit is described for C-Mod, where ∼70% of the current is driven through the bootstrap effect. The LH power is coupled to C-Mod through a waveguide launcher consisting of four rows (vertically) with 24 guides per row (toroidally). A detailed description of the LH launcher fabrication is given in this paper along with initial operation results.

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M3 - Article

AN - SCOPUS:34248180653

SN - 1536-1055

VL - 51

SP - 401

EP - 436

JO - Fusion science and technology

JF - Fusion science and technology

IS - 3

ER -

Wave-particle studies in the ion cyclotron and lower hybrid ranges of frequencies in alcator C-Mod

Abstract

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