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本多 充; 佐竹 真介*; 鈴木 康浩*; 吉田 麻衣子; 林 伸彦; 神谷 健作; 松山 顕之; 篠原 孝司; 松永 剛; 仲田 資季; et al.
Nuclear Fusion, 55(7), p.073033_1 - 073033_11, 2015/07
被引用回数：7 パーセンタイル：28.43(Physics, Fluids & Plasmas)The integrated simulation framework for toroidal momentum transport is developed, which self-consistently calculates the neoclassical toroidal viscosity (NTV), the radial electric field 
and the resultant toroidal rotation 
together with the scrape-off-layer(SOL)-physics based boundary model. The coupling of three codes, the 1.5D transport code, TOPICS, the 3D equilibrium code, VMEC and the 3D 
drift-kinetic equation solver, FORTEC-3D, makes it possible to calculate the NTV due to the non-axisymmetric perturbed magnetic field caused by toroidal field coils. Analyses reveal that the NTV significantly influences in JT-60U and holds the key to determine the NTV profile. The sensitivity of the profile to the boundary rotation necessitates a boundary condition modelling for toroidal momentum. Owing to the high-resolution measurement system in JT-60U, the gradient is found to be virtually zero at the separatrix regardless of toroidal rotation velocities. Focusing on , the boundary model of toroidal momentum is developed in conjunction with the SOL/divertor plasma code D5PM. This modelling realizes self-consistent predictive simulations for operation scenario development in ITER.
本多 充; 佐竹 真介*; 鈴木 康浩*; 松永 剛; 篠原 孝司; 吉田 麻衣子; 松山 顕之; 井手 俊介; 浦野 創
Nuclear Fusion, 54(11), p.114005_1 - 114005_14, 2014/11
被引用回数：15 パーセンタイル：59.18(Physics, Fluids & Plasmas)A cooperation framework for analyses and predictions of the neoclassical toroidal viscosity (NTV) and the resultant toroidal flow is developed among the TOPICS, VMEC and FORTEC-3D codes. With the real geometry in JT-60U taken into account, it is found that the NTV is one of the cardinal torque sources especially in the edge region irrespective of the insertion of the ferritic steel tiles (FSTs) that reduce the toroidal field ripple amplitude and it is essential to numerically reproduce the measured toroidal rotation profile in the edge. The up-down asymmetric component of the NTV is damped due to the FSTs and the NTV profile correlates with the profile of the radial electric field . Predictive simulations for JT-60SA H-mode scenarios are also performed to investigate the effects of the NTV on toroidal rotation. The NTV reversal is observed in the pedestal region where the steep pressure gradient is formed, due to the dependence of the NTV on .
本多 充; 佐竹 真介*; 鈴木 康浩*; 吉田 麻衣子; 林 伸彦; 神谷 健作; 松山 顕之; 篠原 孝司; 松永 剛; 仲田 資季; et al.
Proceedings of 25th IAEA Fusion Energy Conference (FEC 2014) (CD-ROM), 8 Pages, 2014/10
The integrated framework for toroidal momentum transport is developed, which self-consistently calculates the neoclassical toroidal viscosity (NTV), the radial electric field and resultant toroidal rotation together with the scrape-off-layer (SOL) physics-based boundary model. The coupling of three codes, TOPICS, VMEC and FORTEC-3D, can calculate rotation caused by the NTV due to the non-axisymmetric perturbed magnetic field caused by toroidal field coils. It is found that the NTV influences toroidal rotation in JT-60U and holds the key to determine the NTV profile. The sensitivity of the toroidal rotation profile to the boundary rotation necessitates the boundary condition modeling. From the measurement in JT-60U, the gradient is found to be insensitive at the separatrix. Focusing on , the boundary model of toroidal momentum is developed in conjunction with the SOL/divertor plasma code. This modeling realizes self-consistent predictive simulations for operation scenario development in ITER.
鈴木 徹也*; 山中 啓輔*; 石野 まゆ子*; 篠原 康浩*; 長井 健介*; 津留 英司*; 徐 平光
鉄と鋼, 98(6), p.262 - 266, 2012/06
The work-hardening characteristics of anisotropic tensile deformations and the corresponding residual strain changes of pre-strained ferritic steels without and with ageing treatment were investigated by using angle dispersive neutron diffraction and electron back-scattering diffraction. The plastic deformation along the pre-strained direction leads to evident work-hardening at the beginning stage, showing discontinuous yielding behavior. Comparably, the plastic deformation perpendicular to the pre-strained direction shows continuously yielding. The tensile and compressive residual strains were found in the 
200
and 110 grains along the pre-strained direction, respectively. It is also found that the difference in various oriented grains after strain ageing become more evident along the pre-strained direction but smaller perpendicular to the pre-strained direction, revealing a higher work hardening capability in the former case than in the latter case.
本多 充; 佐竹 真介*; 鈴木 康浩*; 松永 剛; 篠原 孝司; 井手 俊介; 吉田 麻衣子; 浦野 創; 林 伸彦
no journal, ,
For simulations of toroidal rotation driven by the neoclassical toroidal viscosity (NTV), the framework of the collaborative execution of the integrated code TOPICS with the 3D equilibrium code VMEC and the 3D neoclassical transport code FORTEC-3D has been developed and improved. In tokamaks, toroidally-asymmetric components of the magnetic field exist and they produce the NTV, which generally slows down toroidal rotation. In JT-60SA H-mode plasmas, somewhat significant impact of the NTV on toroidal rotation is observed and the reversal of the NTV due to the change in the sign of the radial electric field is found in the pedestal. Our framework has been applied to JT-60U analyses. The NTV scales as the perturbed magnetic field strength and the peak of the NTV coincides with the location where 
. The NTV torque is found to be imperative for explaining edge rotation.
本多 充; 佐竹 真介*; 鈴木 康浩*; 松永 剛; 篠原 孝司; 吉田 麻衣子; 浦野 創; 井手 俊介; 林 伸彦
no journal, ,
For simulations of toroidal rotation driven by the neoclassical toroidal viscosity (NTV), the cooperation framework among the integrated transport code TOPICS, the 3D equilibrium code VMEC and the 3D neoclassical transport code FORTEC-3D has been developed. In tokamaks, the toroidally-asymmetric magnetic field perturbatively exist and give rise to the NTV torque, which generally slows down toroidal rotation to. Our framework has been applied to analyses of JT-60U plasmas, which had had large toroidal-field (TF) ripple amplitude due to circular TF coils and the amplitude was reduced by half after ferritic insertion. It has been found that the NTV scales as the perturbed field strength and the NTV peak coincides with the location where . We have better agreement between measurements and simulations in terms of toroidal rotation compared to the cases without the NTV. The results indicate that the NTV torque takes part in one of the key physics that can explain edge rotation.
本多 充; 佐竹 真介*; 鈴木 康浩*; 松永 剛; 篠原 孝司; 吉田 麻衣子; 松山 顕之; 井手 俊介; 浦野 創
no journal, ,
A cooperation framework for analyses and predictions of the neoclassical toroidal viscosity (NTV) and the resultant toroidal flow is developed among the TOPICS, VMEC and FORTEC-3D codes. With the real geometry in JT-60U taken into account, it is found that the NTV is one of the cardinal torque sources especially in the edge region irrespective of the insertion of the ferritic steel tiles (FSTs) that reduce the toroidal field ripple amplitude and it is essential to numerically reproduce the measured toroidal rotation profile in the edge. The up-down asymmetric component of the NTV is damped due to the FSTs and the NTV profile correlates with the profile of the radial electric field.
本多 充; 佐竹 真介*; 鈴木 康浩*; 松永 剛; 篠原 孝司; 吉田 麻衣子; 松山 顕之; 井手 俊介; 浦野 創
no journal, ,
A cooperation framework for analyses and predictions of the neoclassical toroidal viscosity (NTV) and the resultant toroidal flow is developed among the TOPICS, VMEC and FORTEC-3D codes. With the real geometry in JT-60U taken into account, it is found in JT-60U that the NTV is one of the cardinal torque sources especially in the edge region irrespective of the insertion of the ferritic steel tiles (FSTs) that reduce the toroidal field ripple amplitude and it is essential to numerically reproduce the measured toroidal rotation profile in the edge. The up-down asymmetric component of the NTV is damped due to the FSTs and the NTV profile correlates with the profile of the radial electric field.
本多 充; 佐竹 真介*; 鈴木 康浩*; 吉田 麻衣子; 林 伸彦; 神谷 健作; 松山 顕之; 篠原 孝司; 松永 剛; 仲田 資季; et al.
no journal, ,
トカマクの性能予測に向け、新古典トロイダル粘性(NTV), 径電場,トロイダル回転を自己無撞着に計算でき、スクレイプオフ層プラズマの物理も踏まえた境界条件モデルを組み合わせた、トロイダル運動量輸送のための統合フレームワークを構築した。1.5次元輸送・平衡コードTOPICS, 3次元平衡コードVMEC, 新古典輸送コードFORTEC-3Dを組み合わせることで現実的な非軸対称磁場によるNTVを計算できる。NTVは径電場に敏感であり、径電場に大きな影響を与えるトロイダル回転の境界条件モデリングが必須であるため、JT-60Uの径電場観測結果を踏まえた境界条件モデルを構築した。この統合フレームワークによってJT-60Uのトロイダル回転分布をよく再現することができた。またJT-60SAのトロイダル回転分布予測計算を行った。
松永 剛; 鈴木 康浩*; 篠原 孝司; 井手 俊介; 浦野 創
no journal, ,
炉心プラズマの定常維持において、大振幅ELMを抑制または制御する必要がある。ITERでは外部コイルによる共鳴磁場で周辺の閉じ込め磁場をストキャスティック化しELM制御する手法が提案されているが、DEMOにおいては外部コイルの設置は困難である。そこでTFコイルの電流値を周期的に配分し、共鳴磁場を生成する手法を提案する。コイル電流を1%程度増減しトロイダル周期数が3となるように配分すると周辺の磁力線がストキャスティック化する。本発表では、本手法の詳細について報告する。
本多 充; 佐竹 真介*; 鈴木 康浩*; 吉田 麻衣子; 林 伸彦; 神谷 健作; 松山 顕之; 篠原 孝司; 松永 剛; 仲田 資季; et al.
no journal, ,
The integrated framework for toroidal momentum transport in a tokamak plasma is developed, which self-consistently calculates the neoclassical toroidal viscosity (NTV), the radial electric field and resultant toroidal rotation together with the scrape-off-layer (SOL) physics-based boundary model. The coupling of three codes, TOPICS, which is an integrated tokamak transport code developed in JAEA, VMEC, which is a 3D equilibrium solver, and FORTEC-3D, which is a 3D neoclassical transport solver developed in National Institute for Fusion Science, can calculate rotation caused by the NTV due to the non-axisymmetric perturbed magnetic field stemming from toroidal field coils. It is found that the NTV influences toroidal rotation in JT-60U and holds the key to determine the NTV profile. The sensitivity of the toroidal rotation profile to the boundary rotation necessitates the boundary condition modeling. From the measurement in JT-60U, the gradient is found to be virtually zero at the separatrix. Focusing on , the toroidal momentum boundary model is developed in conjunction with the SOL/divertor plasma code. This modeling realizes self-consistent predictive simulations for operation scenario development in ITER.
本多 充; 佐竹 真介*; 鈴木 康浩*; 吉田 麻衣子; 林 伸彦; 神谷 健作; 松山 顕之; 篠原 孝司; 松永 剛; 仲田 資季; et al.
no journal, ,
トカマクの性能予測に向け、新古典トロイダル粘性(NTV),径電場,トロイダル回転を自己無撞着に計算でき、スクレイプオフ層プラズマの物理も踏まえた境界条件モデルを組み合わせた、トロイダル運動量輸送予測のための統合コードを構築した。1.5次元輸送・平衡コードTOPICS, 3次元平衡コードVMEC,新古典輸送コードFORTEC-3Dを組み合わせることで現実的な3次元非軸対称磁場によるNTVを計算できる。NTVは径電場に強い依存性を持つため、径電場に大きな影響を与えるトロイダル回転の境界条件モデリングが必須である。JT-60Uの径電場観測結果からプラズマ境界で径電場の空間勾配がほぼ零であることが分かったため、その事実を元に新しい境界条件モデルを構築した。この統合コードによってJT-60Uのトロイダル回転分布を良く再現することに成功した。またこの統合コードを用いてITERのトロイダル回転分布予測計算を行った。
篠原 孝司; Kim, J.*; Kim, J. Y.*; 鈴木 康浩*
no journal, ,
国際熱核融合炉ITERでは、装置保護のために周辺局在化不安定性(ELM)の制御が求められる。KSTARでは、ELMの制御を目的として共鳴磁場摂動(RMP)印加の実験を行ってきた。しかし、RMPの磁場構造は自明でなく、その理解が求められている。本研究では、KSTARにおいて、RMPの磁場構造を理解するために、RMP印加時の高速イオン損失プローブ計測(FILD)の結果を高速イオン軌道追跡モンテカルロ(OFMC)コードを用いて解析した。モデル磁場として、RMPがない場合、RMPコイルが作る真空磁場、真空磁場にプラズマが応答したことを考慮したモデル磁場を用いた。プラズマ応答を考慮したモデル磁場はHINT2コードを用いて計算した。プラズマ第一壁に到達する高速イオンの分布が磁場構造に対応して、変化することが計算結果として観測された。対応して、FILDに受かる高速イオンの性質も変わるが、いずれの場合も実験を再現できなかった。
篠原 孝司; 鈴木 康浩*; Kim, J.*; Kim, J. Y.*; Jeon, Y. M.*; Rhee, T.*
no journal, ,
建設中の国際熱核融合炉ITERでは、装置保護のために周辺局在化不安定性(ELM)の制御が求められる。ITERでは共鳴磁場摂動コイルを設置し、そのコイルによる摂動磁場によりELM制御を行う予定である。このような摂動磁場は高速イオンの閉じ込めに影響を与えることが予想される。装置保全とプラズマ加熱性能の観点から摂動磁場が高速イオン閉じ込めに与える影響の理解が、重要な話題の一つとなっている。本研究では、高速イオン閉じ込めへの影響をKSTAR(韓国の実験装置)での実験で明らかにするため、KSTARの実験装置や実験条件を忠実に再現して、いくつかの数値モデルによる摂動磁場中での高速イオンの振舞いを高速イオン軌道追跡モンテカルロコードを用いて解析した。KSTARではプラズマ電流が低いことより有限軌道幅の影響が大きく現れ、摂動磁場があると高磁場側で発生した高速イオンであっても数十マイクロ秒という短時間で弱磁場側の壁に損失することがわかった。この高い応答性を利用することで摂動磁場の数値モデルの検証ができると期待できる。
本多 充; 吉田 麻衣子; 佐竹 真介*; 鈴木 康浩*; 林 伸彦; 篠原 孝司; 松山 顕之; 神谷 健作; 松永 剛; 井手 俊介; et al.
no journal, ,
The integrated modeling regarding transport phenomena has progressed significantly in recent years. Toroidal momentum transport and toroidal rotation physics remain less understood than physics of either heat or particles. Developing a integrated code framework especially for toroidal rotation and the radial electric field, which is strongly linked to rotation, can shed light on their understanding and improve the validity of models through comparisons with JT-60U experiments. Toroidal rotation is mainly governed by the balance between torque sources/sinks and momentum transport. We have studied many sorts of torque sources/sinks in tokamaks, that is, NB torque, torque caused by losses and transport of fast and thermal ions due to toroidal field ripple and/or non-axisymmetric perturbed magnetic field, etc. In this talk, emphasis is on the recent development of the integrated modeling regarding rotation and the radial electric field and on the associated physics.
