Formation of oscillating perpendicular electric field by AC limiter biasing on HYBTOK-II tokamak

Uesugi, Yoshihiko; Suzuki, Yasuo; Takamura, S.

doi:10.1016/0022-3115(94)00474-9

Cited by 3 publications

(2 citation statements)

References 5 publications

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“…In the case of resistive plasmas (Lundquist number S ~ 230), the redistribution of the plasma current due to magnetic field reconnection induced by RHF was predominantly observed [9,10]. We have started a new DED experiment on a small tokamak device, HYBTOK-II [11,12] to study the fundamental processes of DED in a higher-temperature region (S ~ 5000) compared with CSTN-IV. It is expected that the shielding current against the externally excited RHF around the resonance surface will drive the plasma poloidal rotation.…”

Section: Introductionmentioning

confidence: 99%

Characteristics of local helical coil system for dynamic ergodic divertor

Kikuchi

Kojima

Taniyama

et al. 2002

Electrical Engineering Japan

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SUMMARYHeat and particle flux control is one of the most important and difficult problems in steady-state fusion devices. The Dynamic Ergodic Divertor (DED) is an advanced concept in which a rotational perturbed magnetic field is applied to make the tokamak edge magnetic structure stochastic so that it may decrease the heat and particle flux onto the local target in the conventional divertor. This rotational perturbed field is created by two sets of local helical coils (LHC) with a phase difference of 90° in the supplied ac currents. In DED experiments, it is important to study the perturbed magnetic field structure generated by these coil currents. In this paper, a new coil configuration is considered, which has an additional series of return windings so as to improve the mode quality of the rotating helical field (RHF). We obtain the mode structure of RHF using a new Fourier analysis. From this result, we confirm that the parasitic mode of RHF and the coil self-inductance are decreased by the new coil configuration. ©

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Section: Introductionmentioning

confidence: 99%

Characteristics of local helical coil system for dynamic ergodic divertor

Kikuchi

Kojima

Taniyama

et al. 2002

Electrical Engineering Japan

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“…Recently, a biased electrode was used to actively control MHD mode rotation on the HBT-EP tokamak [19]. Electrode biasing has also been used to achieve the high confinement H-mode regime as was done in the CCT [20] and HBT-EP [21] tokamaks as well as broaden heat loads at the plasma edge as done in the HYBTOK-II [22] and DIII-D [23] tokamaks. Static electrode biasing has been shown to suppress mode amplitudes in several tokamaks [24][25][26][27][28].…”

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confidence: 99%

Suppression of MHD modes with active phase-control of probe-injected currents

et al. 2021

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Active phase-control of probe-injected current is shown to both suppress and amplify long-wavelength rotating magnetohydrodynamic instabilities in the HBT-EP tokamak. Four probes are connected in quadrature and energized to drive non-axisymmetric currents through the edge of the tokamak, creating magnetic perturbations comparable to previously-studied saturated kink modes or resonant magnetic perturbations that are generated by an external control coil array. Measurements of the magnetic perturbations from the probe-injected currents determine a set of current-carrying helical filaments used to model active feedback control of resistive wall modes. These experiments suggest current-injection feedback may be an effective alternative to external control coils for control of RWMs and other long-wavelength kink-like modes at the edge of tokamaks.

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