Stationary, high bootstrap fraction plasmas in DIII-D without inductive current control

P. A. Politzer; A. W. Hyatt; T. C. Luce; F. W. Perkins; R. Prater; A. D. Turnbull; D. P. Brennan; J. R. Ferron; C. M. Greenfield; J. Jayakumar; R. J. La Haye; C. C. Petty; M. R. Wade

doi:10.1088/0029-5515/45/6/002

Stationary, high bootstrap fraction plasmas in DIII-D without inductive current control

P. A. Politzer, A. W. Hyatt, T. C. Luce, F. W. Perkins, R. Prater, A. D. Turnbull, D. P. Brennan, J. R. Ferron, C. M. Greenfield, J. Jayakumar, R. J. La Haye, C. C. Petty, M. R. Wade

Fusion and Fission Energy and Science Di

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

58 Scopus citations

Abstract

We have initiated an experimental programme to address some of the questions associated with the operation of a tokamak with high bootstrap current fraction under high performance conditions, without assistance from a transformer. In these discharges, stationary (or slowly improving) conditions are maintained for up to 3.7 s at β_N ≈ β_p approaching 3.3. The achievable current and pressure are limited by a relaxation oscillation, involving growth and collapse of an internal transport barrier at ρ ≥ 0.6. The pressure gradually increases and the current profile broadens throughout the discharge. Eventually the plasma reaches a more stable, high confinement (H_89P ∼ 3) state. Characteristically these plasmas have 65-85% bootstrap current, 15-30% neutral-beam-driven current and 0-10% driven by electron cyclotron frequency electromagnetic waves.

Original language	English
Pages (from-to)	417-424
Number of pages	8
Journal	Nuclear Fusion
Volume	45
Issue number	6
DOIs	https://doi.org/10.1088/0029-5515/45/6/002
State	Published - Jun 1 2005

Access to Document

10.1088/0029-5515/45/6/002

Cite this

@article{6084fcccd8324faab4ffb1f668432009,

title = "Stationary, high bootstrap fraction plasmas in DIII-D without inductive current control",

abstract = "We have initiated an experimental programme to address some of the questions associated with the operation of a tokamak with high bootstrap current fraction under high performance conditions, without assistance from a transformer. In these discharges, stationary (or slowly improving) conditions are maintained for up to 3.7 s at βN ≈ βp approaching 3.3. The achievable current and pressure are limited by a relaxation oscillation, involving growth and collapse of an internal transport barrier at ρ ≥ 0.6. The pressure gradually increases and the current profile broadens throughout the discharge. Eventually the plasma reaches a more stable, high confinement (H89P ∼ 3) state. Characteristically these plasmas have 65-85% bootstrap current, 15-30% neutral-beam-driven current and 0-10% driven by electron cyclotron frequency electromagnetic waves.",

author = "Politzer, {P. A.} and Hyatt, {A. W.} and Luce, {T. C.} and Perkins, {F. W.} and R. Prater and Turnbull, {A. D.} and Brennan, {D. P.} and Ferron, {J. R.} and Greenfield, {C. M.} and J. Jayakumar and {La Haye}, {R. J.} and Petty, {C. C.} and Wade, {M. R.}",

year = "2005",

month = jun,

day = "1",

doi = "10.1088/0029-5515/45/6/002",

language = "English",

volume = "45",

pages = "417--424",

journal = "Nuclear Fusion",

issn = "0029-5515",

publisher = "IOP Publishing",

number = "6",

}

TY - JOUR

T1 - Stationary, high bootstrap fraction plasmas in DIII-D without inductive current control

AU - Politzer, P. A.

AU - Hyatt, A. W.

AU - Luce, T. C.

AU - Perkins, F. W.

AU - Prater, R.

AU - Turnbull, A. D.

AU - Brennan, D. P.

AU - Ferron, J. R.

AU - Greenfield, C. M.

AU - Jayakumar, J.

AU - La Haye, R. J.

AU - Petty, C. C.

AU - Wade, M. R.

PY - 2005/6/1

Y1 - 2005/6/1

N2 - We have initiated an experimental programme to address some of the questions associated with the operation of a tokamak with high bootstrap current fraction under high performance conditions, without assistance from a transformer. In these discharges, stationary (or slowly improving) conditions are maintained for up to 3.7 s at βN ≈ βp approaching 3.3. The achievable current and pressure are limited by a relaxation oscillation, involving growth and collapse of an internal transport barrier at ρ ≥ 0.6. The pressure gradually increases and the current profile broadens throughout the discharge. Eventually the plasma reaches a more stable, high confinement (H89P ∼ 3) state. Characteristically these plasmas have 65-85% bootstrap current, 15-30% neutral-beam-driven current and 0-10% driven by electron cyclotron frequency electromagnetic waves.

AB - We have initiated an experimental programme to address some of the questions associated with the operation of a tokamak with high bootstrap current fraction under high performance conditions, without assistance from a transformer. In these discharges, stationary (or slowly improving) conditions are maintained for up to 3.7 s at βN ≈ βp approaching 3.3. The achievable current and pressure are limited by a relaxation oscillation, involving growth and collapse of an internal transport barrier at ρ ≥ 0.6. The pressure gradually increases and the current profile broadens throughout the discharge. Eventually the plasma reaches a more stable, high confinement (H89P ∼ 3) state. Characteristically these plasmas have 65-85% bootstrap current, 15-30% neutral-beam-driven current and 0-10% driven by electron cyclotron frequency electromagnetic waves.

UR - http://www.scopus.com/inward/record.url?scp=19944424155&partnerID=8YFLogxK

U2 - 10.1088/0029-5515/45/6/002

DO - 10.1088/0029-5515/45/6/002

M3 - Article

AN - SCOPUS:19944424155

SN - 0029-5515

VL - 45

SP - 417

EP - 424

JO - Nuclear Fusion

JF - Nuclear Fusion

IS - 6

ER -

Stationary, high bootstrap fraction plasmas in DIII-D without inductive current control

Abstract

Access to Document

Other files and links

Fingerprint

Cite this