Steady-state operation of tokamaks: key experiments, integrated modelling and technology developments on Tore Supra

Key technological and physics issues related to long pulse operation required for a reactor are now being addressed in Tore Supra. This paper focuses on the experimental results from conditions where all the plasma facing components (PFCs) are actively cooled. Full steady-state plasma quantities as well as stable PFC temperature during pulses exceeding 6 min are reported. Particle balance and D retention in the steady-state are analysed. Physics phenomena related to continuous operation are observed in non-inductively driven plasmas, namely (i) a regime characterized by large sinusoidal oscillations of the central electron temperature, governed by a predator–prey mechanism of non-linear coupling between heat transport and plasma current; (ii) a strong synergy effect between lower hybrid and electron cyclotron waves; (iii) a peaked density profile generated by turbulent inward pinch. Integrated modelling activity at Tore Supra is also reported.

[1]  A. Ware.  Pinch-Effect Oscillations in an Unstable Tokamak Plasma , 1970 .

[2]  B. V. Waddell,et al.  Tearing-mode activity for hollow current profiles , 1979 .

[3]  Tadashi Sekiguchi,et al.  Plasma Physics and Controlled Nuclear Fusion Research , 1987 .

[4]  G. Giruzzi.  Modelling of RF current drive in the presence of radial diffusion , 1993 .

[5]  E. Joffrin,et al.  Improved confinement in high li lower hybrid driven steady state plasmas in TORE SUPRA , 1994 .

[6]  M. Porkolab,et al.  Radio frequency power in plasmas , 1994 .

[7]  U. Samm,et al.  Scaling radiative plasmas to ITER , 1997 .

[8]  Peter Lang,et al.  High-efficiency plasma refuelling by pellet injection from the magnetic high-field side into ASDEX upgrade , 1997 .

[9]  O. Naito,et al.  ITER L mode confinement database , 1997 .

[10]  Larry R Baylor,et al.  Radial displacement of pellet ablation material in tokamaks due to the grad-B effect , 2000 .

[11]  P. Hertout,et al.  New advanced launcher for lower hybrid current drive on Tore Supra , 2000 .

[12]  B. Wan,et al.  Plasma density behavior in the Hefei tokamak-7 , 2000 .

[13]  A. Becoulet,et al.  Tore Supra steady-state power and particle injection: the ‘CIMES’ project , 2001 .

[14]  P. T. Bonoli,et al.  Generation of plasma rotation in a tokamak by ion-cyclotron absorption of fast Alfvén waves , 2001 .

[15]  G. T. Hoang,et al.  On the role of ion heating in ICRF heated discharges in Tore Supra , 2001 .

[16]  J. Schlosser,et al.  Experience feedback from high heat flux component manufacturing for Tore Supra , 2001 .

[17]  H. D. Esch,et al.  The Cadarache 1 MV porcelain SINGAP bushing , 2001 .

[18]  T. Fujita,et al.  Plasma equilibrium and confinement in a tokamak with nearly zero central current density in JT-60U. , 2001, Physical review letters.

[19]  Pascal Garin,et al.  Actively cooled plasma facing components in Tore Supra , 2001 .

[20]  L.-G. Eriksson,et al.  Toroidal Plasma Rotation Induced by Fast Ions Without External Momentum Injection in Tokamaks , 2002 .

[21]  B. Coppi,et al.  Accretion theory of `spontaneous' rotation in toroidal plasmas , 2002 .

[22]  Steve C. Chiu,et al.  Radio-frequency-driven radial current and plasma rotation in a tokamak , 2002 .

[23]  Peter Lang,et al.  High β plasmoid formation, drift and striations during pellet ablation in ASDEX Upgrade , 2002 .

[24]  F. Imbeaux,et al.  Simulations of steady-state scenarios for Tore Supra using the CRONOS code , 2003 .

[25]  X. Garbet,et al.  Turbulent particle transport in magnetized plasmas. , 2003, Physical review letters.

[26]  F. Imbeaux,et al.  New tokamak plasma regime with stationary temperature oscillations. , 2003, Physical review letters.

[27]  S. Kawasaki,et al.  Overview of steady state tokamak plasma experiments in TRIAM-1M , 2003 .

[28]  Sylvain Brémond,et al.  The ITER‐like ICRH Launcher Project For JET , 2003 .

[29]  A. Geraud,et al.  A new pellet injector for steady state fuelling in Tore Supra , 2003 .

[30]  R. S. Hemsworth,et al.  Long pulse neutral beam injection , 2003 .

[31]  C. Gil,et al.  Particle pinch with fully noninductive lower hybrid current drive in Tore Supra. , 2003, Physical review letters.

[32]  Investigation of current-density modification during magnetic reconnection by analysis of hydrogen-pellet deflection. , 2003, Physical review letters.

[33]  F. Imbeaux,et al.  MHD activity in Tore Supra gigajoule scenario , 2004 .

[34]  F Imbeaux,et al.  Synergy of electron-cyclotron and lower-hybrid current drive in steady-state plasmas. , 2004, Physical review letters.

[35]  Dennis G. Whyte,et al.  Tritium recovery in ITER by radiative plasma terminations , 2004 .

[36]  C. Gil,et al.  Parametric dependence of turbulent particle transport in tore supra plasmas. , 2004, Physical review letters.

[37]  J. Weiland,et al.  Physics of transport in tokamaks , 2004 .

[38]  G. Falchetto,et al.  Effect of collisional zonal-flow damping on flux-driven turbulent transport. , 2004, Physical review letters.

[39]  A. Becoulet,et al.  Recent fully non-inductive operation results in Tore Supra with 6?min, 1?GJ plasma discharges , 2004 .

[40]  C. Giroud,et al.  The beta scaling of energy confinement in ELMy H-modes in JET , 2004 .

[41]  R. Mitteau,et al.  High heat flux components in fusion devices: from current experience in Tore Supra towards the ITER challenge , 2004 .

[42]  M. Ottaviani,et al.  Multiple states of nonlinear drift-tearing islands. , 2004, Physical review letters.

[43]  M E Fenstermacher,et al.  Suppression of large edge-localized modes in high-confinement DIII-D plasmas with a stochastic magnetic boundary. , 2004, Physical review letters.

[44]  X. Garbet,et al.  Nonlinear dynamics of transport barrier relaxations in tokamak edge plasmas. , 2005, Physical review letters.

[45]  J. Bucalossi,et al.  Pellet fuelling in Tore Supra long discharges , 2005 .

[46]  F. Imbeaux,et al.  MHD stability of fully non-inductive discharges in Tore Supra , 2004, physics/0410181.

[47]  H. Khodja,et al.  Deuterium concentration in deposited carbon layers in Tore Supra , 2005 .

[48]  R. Mitteau,et al.  Role of wall implantation of charge exchange neutrals in the deuterium retention for Tore Supra long discharges , 2005 .