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

59 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

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@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",

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

language = "English",

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pages = "417--424",

journal = "Nuclear Fusion",

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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 - https://www.scopus.com/pages/publications/19944424155

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

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