Evaluation of magnetic fields due to the ferromagnetic vacuum vessel and their influence on plasma discharge in tokamak devices

Nakayama, Tsuneyoshi; Abe, Mitsushi; Tadokoro, Takahiro; Otsuka, M.

doi:10.1016/s0022-3115(98)00806-x

Cited by 27 publications

(8 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the small tokamak, HT-2, ferritic steel (F82H) was installed inside the vacuum vessel. The good compatibility of ferritic steel with an Ohmic heating plasma [7] was demonstrated. To investigate the compatibility with a higher performance plasma, the Advanced Material Tokamak EXperiment (AMTEX) programme is being conducted, in a medium size tokamak, JFT-2M (R = 1.31 m, a 0.35 m, κ 1.7, B t0 2.2 T) [5,[8][9][10][11][12].…”

Section: Introductionmentioning

confidence: 94%

High performance tokamak experiments with a ferritic steel wall on JFT-2M

Tsuzuki¹,

Kimura²,

Kawashima³

et al. 2003

Nucl. Fusion

View full text Add to dashboard Cite

Compatibility between the plasma and low activation ferritic steel, which is a candidate material for fusion demonstration reactors, has been investigated step by step in the JFT-2M tokamak. We have entered the third stage of the Advanced Material Tokamak EXperiment (AMTEX), where the inside of the vacuum vessel wall is completely covered with ferritic steel plates ferritic inside wall (FIW). The effects of a FIW on the plasma production, impurity release, the operation region, and H-mode characteristics have been investigated. No negative effect has been observed up to now. A high normalized beta plasma of β N ∼ 3, having both an internal transport barrier and a steady H-mode edge was obtained. A remarkable reduction in ripple trapped loss from 0.26 MW m −2 (without ferritic steel) to less than 0.01 MW m −2 was demonstrated by the optimization of the thickness profile of FIW. A code to calculate fast ion losses, taking into account the full three-dimensional magnetic structure was developed, and values obtained using the code showed good agreement with experimental results. Thus, encouraging results are obtained for the use of this material in the demo-reactor.

show abstract

Section: Introductionmentioning

confidence: 94%

High performance tokamak experiments with a ferritic steel wall on JFT-2M

Tsuzuki¹,

Kimura²,

Kawashima³

et al. 2003

Nucl. Fusion

View full text Add to dashboard Cite

show abstract

“…The effect of ferritic steel on tokamak plasmas was first investigated experimentally in the small tokamak HT-2 by installing ferritic plates as the first wall. It was shown that normal discharges were possible [3]. However, the effect on plasma stability and its compatibility with improved confinement has not yet been made clear.…”

Section: Introductionmentioning

confidence: 99%

Demonstration of ripple reduction by ferritic steel board insertion in JFT-2M

et al. 2001

Self Cite

View full text Add to dashboard Cite

In the JFT-2M tokamak, the application of low activation ferritic steels to plasmas has been investigated (the so-called Advanced Material Tokamak Experiment (AMTEX) programme). In the first stage, toroidal field ripple reduction was examined by ferritic steel boards (FBs) inserted between the toroidal field coils and the vacuum vessel. It is demonstrated that FB insertion reduced toroidal field ripple and the losses of fast ions produced by tangential co-NBI. By optimizing the FB thickness, such that fundamental mode ripple is minimized to 0.07% at the shoulder of the inside wall, ripple trapped loss is reduced to an almost negligible level. It is determined that the reductions of the fundamental mode ripple and the ripple banana diffusion coefficients at the shoulder are most effective in reducing ripple ion losses. Ripple loss reduction by FBs is also confirmed with perpendicular beam injection. The insertion of FBs causes no undesirable effects on plasma production and control.

show abstract

“…Though the usefulness of ferromagnetic materials for reducing the loss of energetic ions in a TF ripple was proposed by Turner in 1978 [12], ferromagnetic material was not installed on any tokamak for the purpose of the ripple reduction or for the reduction of energetic ion losses until its installation on the JFT-2M tokamak [13,14]. (It should be noted that ferritic steel itself was installed on the HT-2 tokamak which was operated in ohmic heating author's e-mail: shinohara.koji@jaea.go.jp alone [15], not with energetic ions such as neutral beam ions.) In the JFT-2M, two kinds of ripple reductions were carried out.…”

Section: Introductionmentioning

confidence: 99%

Orbit Following Calculation of Energetic Ions in the Design of Ferritic Insertion in the JT-60U

Shinohara

Suzuki

Sakurai

et al. 2006

Plasma and Fusion Research

View full text Add to dashboard Cite

The design process regarding ferritic insertion in the JT-60U is described from the viewpoint of the behavior of energetic ions. The confinement of energetic ions and the absence of unfavorable heat flux on the first wall were assessed using the Fully Three-Dimensional magnetic field OFMC code, which was developed for the toroidal field ripple reduction experiment program utilizing ferritic inserts in the JFT-2M. In the final design, the absorbed power in the neutral beam injection is improved by a factor of about 1.3 in a large volume plasma with B t 0 = 1.9 T.

show abstract

Evaluation of magnetic fields due to the ferromagnetic vacuum vessel and their influence on plasma discharge in tokamak devices

Cited by 27 publications

References 6 publications

High performance tokamak experiments with a ferritic steel wall on JFT-2M

High performance tokamak experiments with a ferritic steel wall on JFT-2M

Demonstration of ripple reduction by ferritic steel board insertion in JFT-2M

Orbit Following Calculation of Energetic Ions in the Design of Ferritic Insertion in the JT-60U

Contact Info

Product

Resources

About