Real-time control of the q-profile in JET for steady state advanced tokamak operation

D. Moreau, F. Crisanti, X. Litaudon, D. Mazon, P. De Vries, R. Felton, E. Joffrin, L. Laborde, M. Lennholm, A. Murari, V. Pericoli-Ridolfini, M. Riva, T. Tala, G. Tresset, L. Zabeo, K.D. Zastrow, EFDA-JET Workprogramme

Research output: Contribution to journalArticleScientificpeer-review

81 Citations (Scopus)

Abstract

In order to simultaneously control the current and pressure profiles in high performance tokamak plasmas with internal transport barriers (ITB), a multi-variable model-based technique has been proposed. New algorithms using a truncated singular value decomposition (TSVD) of a linearized model operator and retaining the distributed nature of the system have been implemented in the JET control system. Their simplest versions have been applied to the control of the current density profile in reversed shear plasmas using three heating and current drive actuators (neutral beam injection, ion cyclotron resonant frequency heating and lower hybrid current drive). Successful control of the safety factor profile has been achieved in the quasi-steady-state, on a timescale of the order of the current redistribution time. How the TSVD algorithm will be used in the forthcoming campaigns for the simultaneous control of the current profile and of the ITB temperature gradient is discussed in some detail, but this has not yet been attempted in the present pioneering experiments.
Original languageEnglish
Pages (from-to)870-882
Number of pages13
JournalNuclear Fusion
Volume43
Issue number9
DOIs
Publication statusPublished - 2003
MoE publication typeA1 Journal article-refereed

Fingerprint

profiles
decomposition
safety factors
heating
quasi-steady states
beam injection
cyclotron frequency
neutral beams
retaining
resonant frequencies
temperature gradients
actuators
current density
shear
operators
ions

Keywords

  • JET
  • plasma
  • Tokamak
  • fusion energy
  • fusion reactors
  • algorithms
  • internal transport barriers

Cite this

Moreau, D., Crisanti, F., Litaudon, X., Mazon, D., De Vries, P., Felton, R., ... Workprogramme, EFDA-JET. (2003). Real-time control of the q-profile in JET for steady state advanced tokamak operation. Nuclear Fusion, 43(9), 870-882. https://doi.org/10.1088/0029-5515/43/9/311
Moreau, D. ; Crisanti, F. ; Litaudon, X. ; Mazon, D. ; De Vries, P. ; Felton, R. ; Joffrin, E. ; Laborde, L. ; Lennholm, M. ; Murari, A. ; Pericoli-Ridolfini, V. ; Riva, M. ; Tala, T. ; Tresset, G. ; Zabeo, L. ; Zastrow, K.D. ; Workprogramme, EFDA-JET. / Real-time control of the q-profile in JET for steady state advanced tokamak operation. In: Nuclear Fusion. 2003 ; Vol. 43, No. 9. pp. 870-882.
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abstract = "In order to simultaneously control the current and pressure profiles in high performance tokamak plasmas with internal transport barriers (ITB), a multi-variable model-based technique has been proposed. New algorithms using a truncated singular value decomposition (TSVD) of a linearized model operator and retaining the distributed nature of the system have been implemented in the JET control system. Their simplest versions have been applied to the control of the current density profile in reversed shear plasmas using three heating and current drive actuators (neutral beam injection, ion cyclotron resonant frequency heating and lower hybrid current drive). Successful control of the safety factor profile has been achieved in the quasi-steady-state, on a timescale of the order of the current redistribution time. How the TSVD algorithm will be used in the forthcoming campaigns for the simultaneous control of the current profile and of the ITB temperature gradient is discussed in some detail, but this has not yet been attempted in the present pioneering experiments.",
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author = "D. Moreau and F. Crisanti and X. Litaudon and D. Mazon and {De Vries}, P. and R. Felton and E. Joffrin and L. Laborde and M. Lennholm and A. Murari and V. Pericoli-Ridolfini and M. Riva and T. Tala and G. Tresset and L. Zabeo and K.D. Zastrow and EFDA-JET Workprogramme",
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Moreau, D, Crisanti, F, Litaudon, X, Mazon, D, De Vries, P, Felton, R, Joffrin, E, Laborde, L, Lennholm, M, Murari, A, Pericoli-Ridolfini, V, Riva, M, Tala, T, Tresset, G, Zabeo, L, Zastrow, KD & Workprogramme, EFDA-JET 2003, 'Real-time control of the q-profile in JET for steady state advanced tokamak operation', Nuclear Fusion, vol. 43, no. 9, pp. 870-882. https://doi.org/10.1088/0029-5515/43/9/311

Real-time control of the q-profile in JET for steady state advanced tokamak operation. / Moreau, D.; Crisanti, F. ; Litaudon, X. ; Mazon, D. ; De Vries, P.; Felton, R. ; Joffrin, E.; Laborde, L.; Lennholm, M.; Murari, A.; Pericoli-Ridolfini, V. ; Riva, M.; Tala, T.; Tresset, G.; Zabeo, L.; Zastrow, K.D.; Workprogramme, EFDA-JET.

In: Nuclear Fusion, Vol. 43, No. 9, 2003, p. 870-882.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

T1 - Real-time control of the q-profile in JET for steady state advanced tokamak operation

AU - Moreau, D.

AU - Crisanti, F.

AU - Litaudon, X.

AU - Mazon, D.

AU - De Vries, P.

AU - Felton, R.

AU - Joffrin, E.

AU - Laborde, L.

AU - Lennholm, M.

AU - Murari, A.

AU - Pericoli-Ridolfini, V.

AU - Riva, M.

AU - Tala, T.

AU - Tresset, G.

AU - Zabeo, L.

AU - Zastrow, K.D.

AU - Workprogramme, EFDA-JET

PY - 2003

Y1 - 2003

N2 - In order to simultaneously control the current and pressure profiles in high performance tokamak plasmas with internal transport barriers (ITB), a multi-variable model-based technique has been proposed. New algorithms using a truncated singular value decomposition (TSVD) of a linearized model operator and retaining the distributed nature of the system have been implemented in the JET control system. Their simplest versions have been applied to the control of the current density profile in reversed shear plasmas using three heating and current drive actuators (neutral beam injection, ion cyclotron resonant frequency heating and lower hybrid current drive). Successful control of the safety factor profile has been achieved in the quasi-steady-state, on a timescale of the order of the current redistribution time. How the TSVD algorithm will be used in the forthcoming campaigns for the simultaneous control of the current profile and of the ITB temperature gradient is discussed in some detail, but this has not yet been attempted in the present pioneering experiments.

AB - In order to simultaneously control the current and pressure profiles in high performance tokamak plasmas with internal transport barriers (ITB), a multi-variable model-based technique has been proposed. New algorithms using a truncated singular value decomposition (TSVD) of a linearized model operator and retaining the distributed nature of the system have been implemented in the JET control system. Their simplest versions have been applied to the control of the current density profile in reversed shear plasmas using three heating and current drive actuators (neutral beam injection, ion cyclotron resonant frequency heating and lower hybrid current drive). Successful control of the safety factor profile has been achieved in the quasi-steady-state, on a timescale of the order of the current redistribution time. How the TSVD algorithm will be used in the forthcoming campaigns for the simultaneous control of the current profile and of the ITB temperature gradient is discussed in some detail, but this has not yet been attempted in the present pioneering experiments.

KW - JET

KW - plasma

KW - Tokamak

KW - fusion energy

KW - fusion reactors

KW - algorithms

KW - internal transport barriers

U2 - 10.1088/0029-5515/43/9/311

DO - 10.1088/0029-5515/43/9/311

M3 - Article

VL - 43

SP - 870

EP - 882

JO - Nuclear Fusion

JF - Nuclear Fusion

SN - 0029-5515

IS - 9

ER -

Moreau D, Crisanti F, Litaudon X, Mazon D, De Vries P, Felton R et al. Real-time control of the q-profile in JET for steady state advanced tokamak operation. Nuclear Fusion. 2003;43(9):870-882. https://doi.org/10.1088/0029-5515/43/9/311