On the modelling of fast particle ripple losses in tokamaks

Putvinskij, S.V.; Tubbing, B.J.D.; Eriksson, L.‐G.; Коновалов, С. В.

doi:10.1088/0029-5515/34/4/i03

Cited by 33 publications

(23 citation statements)

References 12 publications

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“…Both the steady-state and dynamic magnetic fields are now influenced by the magnetization and eddy currents within ferritic components. Improper placement of ferromagnetic components can increase undesirable error fields and hinder tokamak performance, 8 and ferritic material near the plasma surface weakens MHD stability by introducing the ferritic wall mode (FWM). [9][10][11] Because the use of ferritic materials will likely be mandatory in ITER and DEMO, 12 ferritic wall studies are both timely and important.…”

Section: Introductionmentioning

confidence: 99%

Active and passive kink mode studies in a tokamak with a movable ferromagnetic walla)

et al. 2015

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High-resolution active and passive kink mode studies are conducted in a tokamak with an adjustable ferromagnetic wall near the plasma surface. Ferritic tiles made from 5.6 mm thick Hiperco V R 50 alloy have been mounted on the plasma-facing side of half of the in-vessel movable wall segments in the High Beta Tokamak-Extended Pulse device [D. A. Maurer et al., Plasma Phys. Controlled Fusion 53, 074016 (2011)] in order to explore ferritic resistive wall mode stability. Low-activation ferritic steels are a candidate for structural components of a fusion reactor, and these experiments examine MHD stability of plasmas with nearby ferromagnetic material. Plasma-wall separation for alternating ferritic and non-ferritic wall segments is adjusted between discharges without opening the vacuum vessel. Amplification of applied resonant magnetic perturbations and plasma disruptivity are observed to increase when the ferromagnetic wall is close to plasma surface instead of the standard stainless steel wall. Rapidly rotating m=n ¼ 3=1 external kink modes have higher growth rates with the nearby ferritic wall. Feedback suppression of kinks is still as effective as before the installation of ferritic material in vessel, in spite of increased mode growth rates. V C 2015 AIP Publishing LLC. [http://dx.

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Section: Introductionmentioning

confidence: 99%

Active and passive kink mode studies in a tokamak with a movable ferromagnetic walla)

et al. 2015

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“…Efforts to include both effects for specific tokamak experiments have, up to this point, been limited to calculations for a few cases on JT-6OU [17, 261 and JET [25]. Similar extensive computations [21- This is an important issue for the design of future tokamak reactors such as ITER because stochastic ripple diffusion of alpha particles deposits a strongly localized heat load on the first wall.…”

Section: Introductioiimentioning

confidence: 99%

Collisional stochastic ripple diffusion of alpha particles and beam ions on TFTR

et al. 1995

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Predictions for ripple loss of fast ions from TFTR are investigated with a guiding centre code including both collisional and ripple effects. A synergistic enhancement of fast ion diffusion is found for toroidal field ripple with collisions. The total loss is calculated to be roughly twice the sum of ripple and collisional losses calculated separately. Discrepancies between measurements and calculations of plasma beta at low current and large major radius are resolved when both effects are included for neutral beam ions. A 20 to 30% reduction in alpha particle heating is predicted for qa=6-14, R=2.6 m DT plasmas on TFTR owing to first orbit and collisional stochastic ripple diffusion

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“…This model does not include any fast-ion diffusion (only loss), therefore it does not simulate the gradual transport of beam ions outwards. predict the profile data utilizing the fast-ion distribution function calculated by Monte Carlo [33] or Fokker-Planck [34] codes that include the effects of stochastic ripple diffusion.…”

Section: Discussionmentioning

confidence: 99%

Evidence for spatially variable beam ion diffusion in TFTR

Ruskov¹,

Heidbrink²,

McCune³

et al. 1996

Plasma Phys. Control. Fusion

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Abstract. We present evidence that the fast-ion diffusion coefficient changes across the TFTR plasma column. Two MHD quiescent discharges are analysed: a high power D-T plasma heated with 21 MW of deuterium and tritium beams, and an ohmic plasma into which a 10 MW, 20 ms deuterium beam pulse was injected. The localized charge-exchange measurements in the ohmic plasma, and the neutron flux measurements in the D-T plasma are compared with predictions from the 1 1 2 D transport simulation code TRANSP. We have modified the code to allow modelling with arbitrary fast-ion diffusion profiles D f (r). Significant improvement in the agreement between measurement and simulation is obtained with a D f (r) profile that has low values in the inner half of the plasma column (D f < 0.05 m 2 s −1 ) and then rises rapidly towards the plasma periphery. This suggests a common underlying mechanism of enhanced beam ion transport in the two discharges, such as stochastic ripple diffusion.

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On the modelling of fast particle ripple losses in tokamaks

Cited by 33 publications

References 12 publications

Active and passive kink mode studies in a tokamak with a movable ferromagnetic walla)

Active and passive kink mode studies in a tokamak with a movable ferromagnetic walla)

Collisional stochastic ripple diffusion of alpha particles and beam ions on TFTR

Evidence for spatially variable beam ion diffusion in TFTR

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