Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Arokiaswamy, J. A.*; Batra, C.*; Chang, J. E.*; Garcia, M.*; Herranz, L. E.*; Klimonov, I. A.*; Kriventsev, V.*; Li, S.*; Liegeard, C.*; Mahanes, J.*; et al.
IAEA-TECDOC-2006, 380 Pages, 2022/00
IAEAの共同研究プロジェクト「シビアアクシデント条件下におけるプロトタイプナトリウム冷却高速炉からの放射性物質の放出」は、シビアアクシデント条件下における、リファレンスとなるナトリウム冷却高速炉の施設内における放射性物質および燃料粒子の存在量の、異なる時間スケールにおける現実的な数値シミュレーションを目的として実施された。解析のスコープは3つに分割され、3つのワークパッケージ(WP)として定義された:(1)炉内ソースターム評価、(2)一次系/格納容器系境界のソースターム評価、および(3)格納容器内の現象分析。WP-1の参加機関の結果を比較すると、希ガスおよび放射性セシウムの放出割合、およびカバーガスへの放射性核種の放出割合はよく一致した。共通の圧力履歴を用いたWP-2の解析では、各機関の解析結果はよく一致し、いずれの機関の解析手法も同程度の精度を有することが示された。先行するWPにおける解析と分離するため、放出割合をあらかじめ設定したスタンドアロンケースがWP-3にて定義された。WP-3の全参加機関によるスタンドアロンケースの解析結果は全般的に一致した。
Garcia, J.*; 林 伸彦; Baiocchi, B.*; Giruzzi, G.*; 本多 充; 井手 俊介; Maget, P.*; 成田 絵美*; Schneider, M.*; 浦野 創; et al.
Nuclear Fusion, 54(9), p.093010_1 - 093010_13, 2014/09
被引用回数：38 パーセンタイル：86.63(Physics, Fluids & Plasmas)Extensive physics analysis and modelling has been undertaken for the typical operational regimes of the tokamak devices JET and JT-60U with the aim of extrapolating present day experiments to JT-60SA, which shares important characteristics with both tokamaks. A series of representative discharges of two operational scenarios, H-mode and hybrid, have been used for this purpose. Predictive simulations of core turbulence, particle transport, current diffusion and pedestal pressure have been carried out with different combinations of models. The ability of the models for reproducing the experimental data is analysed and scenario calculations for JT-60SA are performed following an optimum set of models.
Garcia, J.*; 林 伸彦; Giruzzi, G.*; Schneider, M.*; Joffrin, E.*; 井手 俊介; 坂本 宜照; 鈴木 隆博; 浦野 創; JT-60チーム; et al.
Europhysics Conference Abstracts (Internet), 38F, p.P1.029_1 - P1.029_4, 2014/06
Creation of JT-60SA scenarios is necessary in order to make deeper analyses: Fast ions, heating schemes, MHD. Validation exercise: a series of representative discharges of the three main operational scenarios, H-mode, hybrid and steady-state have been selected for each device in order to extrapolate to JT-60SA. An extensive analysis of the main physics similarities and differences among the discharges has been carried out in order to explain results. Using integrated modelling codes CRONOS and TOPICS, benchmark of the codes is done. Predictive core turbulence simulations have been carried out with three transport models: Bohm-GyroBohm, CDBM and GLF23. Particle transport is analyzed with GLF23. Pressure pedestal predictions are simulated with Cordey MHD scaling. Fully predictive simulations of temperatures, density and pedestal have been performed with GLF23 and CDBM models for the temperatures and GLF23 for the density. Calculations for JT-60SA are performed following the best combination of models found.
Luce, T. C.*; Challis, C. D.*; 井手 俊介; Joffrin, E.*; 鎌田 裕; Politzer, P. A.*; Schweinzer, J.*; Sips, A. C. C.*; Stober, J.*; Giruzzi, G.*; et al.
Nuclear Fusion, 54(1), p.013015_1 - 013015_15, 2013/12
被引用回数：35 パーセンタイル：83.31(Physics, Fluids & Plasmas)The ITPA IOS group has coordinated experimental and modeling activity on the development of advanced inductive scenarios for applications in the ITER tokamak. This report documents the present status of the physics basis and the prospects for applications in ITER. The key findings are: (1) inductive scenarios capable of higher 
than the ITER baseline scenario (
) with normalized confinement at or above the standard H-mode scaling have been established under stationary conditions on the four largest diverted tokamaks (AUG, DIII-D, JET, JT-60U) in a broad range in 
and density; (2) MHD modes can play a key role in reaching stationary high performance, but also define the stability and confinement limits; (3) the experiments have yielded clearer measurements of the normalized gyroradius scalin; and (4) coordinated modeling activity supports the present research by clarifying the most significant uncertainties in the projections to ITER.
Giruzzi, G.*; Garcia, J.*; 林 伸彦; Schneider, M.*; Artaud, J. F.*; Baruzzo, M.*; Bolzonella, T.*; Farina, D.*; Figini, L.*; 藤田 隆明; et al.
Proceedings of 24th IAEA Fusion Energy Conference (FEC 2012) (CD-ROM), 8 Pages, 2013/03
A coordinated Japan-EU modelling activity has started in order to provide predictive simulations of the main JT-60SA scenarios. The first results of this activity are discussed in this paper. This includes: (1) the critical comparison and benchmark of Japanese and EU H and CD codes, in particular of NBI codes for the complex injector configuration of the JT-60SA machine; (2) the validation of the main models and simulation framework used in both Japanese and EU integrated modelling suites of codes, based on selected reference discharges of JT-60U and JET, representing the main scenarios (H-mode, hybrid, advanced); (3) predictive modelling of JT-60SA scenario, using the 0.5-D code METIS.
Garcia, J.*; 林 伸彦; Giruzzi, G.*; Schneider, M.*; Joffrin, E.*; 井手 俊介; 坂本 宜照; 鈴木 隆博; 浦野 創; JT-60チーム; et al.
Europhysics Conference Abstracts (Internet), 36F, p.P5.057_1 - P5.057_4, 2012/00
Predictive simulations for electron and ion temperatures have been carried out for JET and JT-60U plasmas in order to determine the most appropriate models to this type of plasmas. To carry out this programme, the integrated modelling codes CRONOS and TOPICS-IB are used. Results show that the H-modes are usually well simulated for both devices, whereas for the advanced regimes, as the hybrid, there are clear deviations from experimental data, mainly for JT-60U. The reasons for such discrepancies are analysed.
Imbeaux, F.*; Citrin, J.*; Hobirk, J.*; Hogeweij, G. M. D.*; K
chl, F.*; Leonov, V. M.*; 宮本 斉児; 中村 幸治*; Parail, V.*; Pereverzev, G. V.*; et al.
Nuclear Fusion, 51(8), p.083026_1 - 083026_11, 2011/08
被引用回数：35 パーセンタイル：80.49(Physics, Fluids & Plasmas)In order to prepare adequate current ramp-up and ramp-down scenarios for ITER, present experiments from various tokamaks have been analysed by means of integrated modelling in view of determining relevant heat transport models for these operation phases. A set of empirical heat transport models for L-mode has been validated on a multi-machine experimental dataset for predicting the 
dynamics within 
0.15 accuracy during current ramp-up and ramp-down phases. The most accurate heat transport models are then applied to projections to ITER current ramp-up, focusing on the baseline inductive scenario (main heating plateau current of 
MA). These projections include a sensitivity study to various assumptions of the simulation. While the heat transport model is at the heart of such simulations, more comprehensive simulations are required to test all operational aspects of the current ramp-up and ramp-down phases of ITER scenarios. Recent examples of such simulations, involving coupled core transport codes, free-boundary equilibrium solvers and a poloidal field (PF) systems controller are also described, focusing on ITER current ramp-down.
村上 和功*; Park, J. M.*; Giruzzi, G.*; Garcia, J.*; Bonoli, P.*; Budny, R. V.*; Doyle, E. J.*; 福山 淳*; 林 伸彦; 本多 充; et al.
Proceedings of 23rd IAEA Fusion Energy Conference (FEC 2010) (CD-ROM), 8 Pages, 2011/03
Recent progress on ITER steady-state scenario modeling by the ITPA-IOS group is reviewed. Code-to-code benchmarks as the IOS group's common activities for the two steady-state scenarios (weak shear scenario and internal transport barrier scenario) are reviewed. These are discussed in terms of transport and kinetic profiles, heating and CD sources using various transport codes.
Imbeaux, F.*; Basiuk, V.*; Budny, R.*; Casper, T.*; Citrin, J.*; Fereira, J.*; 福山 淳*; Garcia, J.*; Gribov, Y. V.*; 林 伸彦; et al.
Proceedings of 23rd IAEA Fusion Energy Conference (FEC 2010) (CD-ROM), 8 Pages, 2011/03
In order to prepare adequate current ramp-up and ramp-down scenarios for ITER, present experiments from various tokamaks have been analysed by means of integrated modelling in view of determining relevant heat transport models for these operation phases. The most accurate heat transport models are then applied to projections to ITER current ramp-up, focusing on the baseline inductive scenario (main heating plateau current of Ip = 15 MA). These projections include a sensitivity studies to various assumptions of the simulation. Recent examples of such simulations, involving coupled core transport codes, free boundary equilibrium solvers and a poloidal field (PF) systems controller are described in the second part of the paper, focusing on ITER current ramp-down.
Imbeaux, F.*; Basiuk, V.*; Budny, R.*; Casper, T.*; Citrin, J.*; Fereira, J.*; 福山 淳*; Garcia, J.*; Gribov, Y. V.*; 林 伸彦; et al.
Proceedings of 23rd IAEA Fusion Energy Conference (FEC 2010) (CD-ROM), 8 Pages, 2010/10
ITERでの電流立ち上げ・立ち下げシナリオの準備に向けて、これら運転状態においてどの熱輸送モデルが適切であるかを決定するために、代表的なトカマクでの現在の実験結果を統合モデルシミュレーションにより解析した。本研究では、トカマク実験の解析結果をもとに、ITER標準誘導運転(プラズマ電流15MA)の電流立ち上げ・立ち下げシナリオでの予測を行った。統合モデルシミュレーション結果を、ASDEX Upgrade, C-Mod, DIII-D, JET, Tore Supraのオーミック加熱プラズマ及び外部加熱・電流駆動プラズマ実験データと比較することにより、さまざまな輸送モデルの検証を行った。最も実験結果の再現性の良かった幾つかのモデルを用いて、ITERの電流立ち上げ・立ち下げ段階での電子密度・電流密度プロファイルの予測を行った。電子温度プロファイルには輸送モデルによって大きな差が見られたが、最終的な電流密度プロファイルはモデル間でよく一致することがわかった。
西森 信行; Bazarov, I.*; Dunham, B.*; Grames, J.*; Hernandez-Garcia, C.*; Jones, L.*; Militsyn, B.*; Poelker, M.*; Surles-Law, K.*; 山本 将博*
Proceedings of 45th Advanced ICFA Beam Dynamics Workshop on Energy Recovery Linacs (ERL '09) (Internet), p.6 - 23, 2009/06
This paper summarizes technological challenges of photoemission DC guns being developed for the future energy recovery linac (ERL) light sources (LS). Anticipated new applications of ERL-LS demand an electron gun capable of producing an extremely low emittance beam at very high average current. The low emittance requires unprecedentedly high voltage equal to or greater than 500 kV between cathode/anode electrodes together with high accelerating gradient on the photocathode. The technological challenge is to develop a high voltage insulator system, which can withstand field emission from the electrodes. The high average current requires prolonged cathode life time, which is governed by ion back-bombardment. Challenges to mitigate the cathode damage caused by ion back-bompardment are surveyed. A gun geometry satisfying both high gun voltage and high accelerating gradient is also proposed.
Giruzzi, G.*; Park, J. M.*; Murakami, M.*; Kessel, C. E.*; Polevoi, A.*; Sips, A. C. C.*; Artaud, J. F.*; Basiuk, V.*; Bonoli, P.*; Budny, R. V.*; et al.
Proceedings of 22nd IAEA Fusion Energy Conference (FEC 2008) (CD-ROM), 8 Pages, 2008/10
The modeling of the steady-state ITER scenarios is reviewed, as a subject of common work of the ITPA-SSO group. Focus is made not only on the basic physics issues, resulting from theory and experiments, but also on the difficulties and the needs of integrated modeling. Specific issues connected with high bootstrap fraction in the long pulse operation are addressed. Bootstrap current can be enhanced either by large pedestal temperatures, or by Internal Transport Barriers (ITB). Recent simulations for both high-pedestal scenarios and ITB scenarios are compared. Results of code benchmarking for typical parameters of ITER scenarios are also analyzed, and prospects for improvement of the integrated modeling capability will be discussed.
Kessel, C. E.*; Giruzzi, G.*; Sips, A. C. C.*; Budny, R. V.*; Artaud, J. F.*; Basiuk, V.*; Imbeaux, F.*; Joffrin, E.*; Schneider, M.*; Luce, T.*; et al.
Proceedings of 21st IAEA Fusion Energy Conference (FEC 2006) (CD-ROM), 8 Pages, 2007/03
国際トカマク物理活動の定常運転グループでは統合シミュレーションコードのベンチマークを始めており、CRONOS, ONETWO, TRANSP, TOPICS, ASTRAといった複数の1.5次元輸送コードを用いてITERハイブリッド運転のシミュレーションを行った。平衡配位,加熱電流駆動機器のジオメトリ、熱・粒子輸送モデル等について共通ガイドラインを設けて極力同じ計算条件となるようにしている。世界的に利用されている輸送コードのほとんどが参加したベンチマークは初めてであり、結果の違いについて結論できる段階には至っていないが、各コードにおいて改良すべき点を客観的に評価できることを明らかにした。
Rao, T.*; Burrill, A.*; Chang, X. Y.*; Smedley, J.*; 西谷 智博; Hernandez Garcia, C.*; Poelker, M.*; Seddon, E.*; Hannon, F. E.*; Sinclair, C. K.*; et al.
Nuclear Instruments and Methods in Physics Research A, 557(1), p.124 - 130, 2006/02
被引用回数：59 パーセンタイル：96.04(Instruments & Instrumentation)近年、次期光源や高エネルギー核物理学に用いるエネルギー回収型線形加速器(ERL)の利用が注目を浴びている。ERLが要求する電子源性能は、電流値、電流密度、繰り返し、温度や加速勾配など広範囲に渡る。これらの性能を実現する電子源として、光陰極電子源が重要な役割を果たすと考えられている。本論文では、ERLを実現しうる二次電子放出型、セシウム付加ディスペンサー型、フィールドエミッタ型や超格子半導体の光陰極電子源について概論を提供する。
Garcia, J.*; 林 伸彦; Baiocchi, B.*; Citrin, J.*; Giruzzi, G.*; 本多 充; 井手 俊介; Maget, P.*; 成田 絵美*; Schneider, M.*; et al.
no journal, ,
An extensive exercise of physics analysis and modeling has been undertaken for the typical operational regimes of the tokamak devices JET and JT-60U with the aim of extrapolating present day experiments to JT-60SA, which share characteristics with both tokamaks. A series of representative discharges of two operational scenarios, H-mode and hybrid have been used for this purpose. Predictive simulations of core turbulence, particle transport, current diffusion and pedestal pressure have been carried out with different combination of models. The ability of the models for reproducing the experimental data is analyzed and scenario calculations for JT-60SA are performed following an optimum simulation framework.
Garzotti, L.*; Barbato, E.*; Garcia, J.*; Romanelli, M.*; Stankiewicz, R.*; 林 伸彦; 吉田 麻衣子
no journal, ,
JT-60SA scenarios have been simulated with different codes and transport models. Aim of the simulations was to assess stationary conditions estimated with 0-dimensional codes and provide a profile database for further physics studies. Three scenarios considered are standard H-mode, hybrid, advanced steady-state. Codes deployed are ASTRA, CRONOS, JINTRAC. Core transport models used are TGLF (CRONOS), CDBM (CRONOS), GLF23 (ASTRA, CRONOS), Bohm/gyro-Bohm (ASTRA, JINTRAC). Edge transport barrier models are continuous ELMs (JINTRAC), Cordey scaling + EPED1 (CRONOS). Boundary conditions are imposed at separatrix (CRONOS JINTRAC) or top of the pedestal (ASTRA). Fully predictive simulations of current density, ion density (CRONOS and JINTRAC, density not evolved in ASTRA), ion and electron temperature. No rotation. Equilibrium solver SPIDER or three moments (ASTRA), HELENA (CRONOS) and ESCO (JINTRAC). Results are close to those obtained with zero-dimensional codes. Detail of the profiles differ from code to code. Electron and ion temperatures assumed in zero-dimensional calculations seem to be optimistic for most scenarios. For all scenarios normalized pedestal pressure seems to be below MHD stability limit. Further analysis of pedestal stability is required. Analysis of time dependent scenarios (density and current ramp up and down) is planned.
