Dynamic interaction between disruptive plasma and wall in the small tokamak HYBTOK-II

Okamoto, M.; Yamada, Toshiro; Hiraishi, Tetsuya; Kikuchi, Yusuke; Ohno, Noriyasu; Takamura, S.

doi:10.1016/j.jnucmat.2007.01.141

Cited by 3 publications

(3 citation statements)

References 4 publications

(1 reference statement)

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“…Zero in time corresponds to the initiating time of CQ. Disruption was driven by ramping up I p to reduce the plasma surface safety factor q a (= aB t /RB θ ), where B t and B θ are the toroidal and poloidal magnetic field strengths, respectively [14,15]. The typical parameters just before CQ are as follows: plasma minor radius is approximately 9.5 ∼ 10.5 cm, q a ∼ 3, I p = 10-11 kA, and B t ∼ 0.25 T. It is found that the waveform of CQ consists of two phases of slow and fast current decays in the HYBTOK-II disruptions as shown in Fig.…”

Section: Waveform Of Disruptive Discharge In Hybtok-ii Tokamakmentioning

confidence: 99%

Systematic Analysis of Current Decay Time during Disruption in HYBTOK-II Tokamak

Okamoto

Ohno

Takamura

2008

Plasma and Fusion Research

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In order to estimate the electromagnetic force acting on vessel components during tokamak disruptions, an accurate prediction of the plasma current decay time is necessary. We have verified a current decay model based on a simple series circuit with a plasma resistance and an inductance. The circuit is employed for establishment of a plasma current decay time database using disruptive discharges in a small tokamak HYBTOK-II. An increase in the decay rate of the plasma current during the current quench phase was observed in experiments associated with an increase in the plasma resistance. This experimental result is consistent with the prediction of the model.

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Section: Waveform Of Disruptive Discharge In Hybtok-ii Tokamakmentioning

confidence: 99%

Systematic Analysis of Current Decay Time during Disruption in HYBTOK-II Tokamak

Okamoto

Ohno

Takamura

2008

Plasma and Fusion Research

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“…Figure 10 shows the temporal evolution of electron density and pressure at the edge, which is obtained by averaging over the area between r = 5.5 cm and 10 cm, at around the current quench. After the pump-out of plasma particle, n e at the edge region increases because hydrogen recycling is enhanced due to an increase in the interaction between the plasma and the wall [13]. The area averaged electron pressure becomes maximum just after current quench starting time.…”

Section: Growth Of Tearing Modementioning

confidence: 99%

Integrated view of disruption dynamics on internal electromagnetic and plasma structures in the small tokamak HYBTOK-II

et al. 2007

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Integrated view of disruption dynamics on internal electromagnetic and plasma structures with a high time resolution is presented systematically. Main results are as follows: (i) Observation of electron temperature oscillation due to rotation of the magnetic island of m/n = 3/2 mode before the current quench and (ii) finding of rapid pump-out (~ 10 µs) of plasma current and particles from the central core region just at current quench start time and then returning to a peaked profile during slow decay phase, and (iii) new proposal for the evaluation of current quench time and electron temperature dependence in the current quench time, so called τ /S scaling.

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“…No theoretical explanation has been published so far, only few work has been reported in the literature, which are only linked with experimental details, that is, Okamoto et al gives the interaction between plasma disruption and wall in HYBTOK-II tokamak by using triple probe. They observed that wave form of plasma quench has two phases, that is, slow and then fast decay process that influence the rapid movement of plasma to the inner wall as well [9]. • J. Li et al find out the effect of plasma disruption on magnetic system in EAST tokamak and calculates the temperature effect experimentally [10].…”

Section: Introductionmentioning

confidence: 99%

Theoretical investigation of plasma dynamical behavior and halo current analysis

Khan

Song

Khan

2015

Int. J. Energy Res.

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In this paper, a novel system has been developed for plasma disruption conditions followed by downward vertical displacement. During the disruption, size and orientation of plasma decreases, which gives the halo current circulated around each contacting point in radial as well as in poloidal directions. Therefore, a new mathematical model has been developed, which gives the interaction forces of halo current, vertical, and radial plasma dynamical behavior (linear and nonlinear). This theoretical approach showed that the tokamak plasma has two connecting points in order to distinguish between the stable and unstable position. This model can particularly give the magnetic field change points and changing of flux, which are more convenient in order to discuss the static and tilting position of plasma behavior. Numerical techniques have been calculated in terms of plasma dynamical behavior, that is, Electromagnetic/plasma, Vertical Displacement Event (VDE) stages, and initial interaction between the forces under specific time interval. The objective of the research is to developed theoretical and computational model in order to investigate the dynamical behavior of plasma under disruption conditions. This is the novel method, and no work has been reported so far.

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Dynamic interaction between disruptive plasma and wall in the small tokamak HYBTOK-II

Cited by 3 publications

References 4 publications

Systematic Analysis of Current Decay Time during Disruption in HYBTOK-II Tokamak

Systematic Analysis of Current Decay Time during Disruption in HYBTOK-II Tokamak

Integrated view of disruption dynamics on internal electromagnetic and plasma structures in the small tokamak HYBTOK-II

Theoretical investigation of plasma dynamical behavior and halo current analysis

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