Relationship between fuelling profile and structure and structure formation in boundary region of fusion plasmas

聚变等离子体边界区域的燃料供给剖面与结构和结构形成之间的关系

• 批准号: 17360447
• 负责人: TAKENAGA Hidenobu
• 金额: $ 9.35万
• 依托单位: Japan Atomic Energy Agency
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2005
• 资助国家: 日本
• 起止时间: 2005 至 2007
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-17360447/
• 关键词: Fuelling profile; Boundary region of fusion plasma; Self-formed structure; Edge pedestal; Gas-puffing; Pellet injector; Gas-jet; Confinement; 周辺ペデスタル; 高磁場側ガス供給; プラズマ・核融合; 燃焼プラズマ制御

The objective of this research is to understand relationship between fuelling profile and spatial structure of edge pedestal (i.e. its width and gradient) which is self-formed in the boundary region of fusion plasmas. A new fuelling device gas-jet has been installed on JT-60U in collaboration with CEA-Cadarache, France. Gas jet can inject supersonic gas into plasmas and it has intermediate fuelling profile between those of gas-puffing and pellet injector which are so far used in JT-60U. It was critical issue for the installation to avoid damage of the vacuum seal placed in the injector head owing to high baking temperature for the JT-60U vacuum vessel (〜300 degree C). By applying high heat resistant material, high feeding gas pressure during the baking to reduce the stresses on the seal and reduction of baking temperature to 〜80 degree C, gas jet was successfully injected in the large tokamak plasma for the first time. Density jumps were observed with the background gas pressure of 4-6 bar and the frequency of 4-10 Hz. Although light from the gas jet was almost emitted outside the separatrix, quick decreases in the ion temperature were observed even at a normalized minor radius of 〜0.8. The gas jet could directory affect the plasma parameters at this point. Inside this point, cold pulse propagated into the central region. The pedestal electron pressure determined by the edge pedestal structure was kept constant, because the temperature was decreased with increasing the density. Enhancement of the edge pressure was not observed with gas-jet, while it was observed with high-field-side pellet injections. The pedestal ion temperature was also decreased with the gas-jet. Confinement degraded when the density was increased with the gas-jet. In future, it is important to investigate parameter dependence of the pedestal structure in the wide experimental ranges for background gas pressure and frequency.

研究了聚变等离子体边界区自形成的边缘基座的空间结构（即宽度和梯度）与加料剖面的关系。与法国CEA-Cadarache合作，在JT-60 U上安装了一个新的加油装置气体喷射器。气体射流能将超音速气体注入等离子体中，它具有介于目前JT-60 U上使用的喷气式和弹丸式注入器之间的中间型加料剖面。JT-60 U真空罐烘烤温度高（≥ 300 ℃），如何避免真空密封损坏是安装中的关键问题。通过采用高耐热材料、提高烘烤时的供气压力以减小密封件上的应力以及将烘烤温度降低到1080 ℃，首次成功地在大型托卡马克等离子体中注入了气体射流。在背景气压为4-6巴和频率为4-10 Hz的情况下观察到密度跳跃。虽然来自气体射流的光几乎被发射到分界线之外，但即使在归一化的小半径为0.8时，也观察到离子温度的快速下降。此时气体射流会直接影响等离子体参数。在此点内，冷脉冲传播到中心区域。边缘基座结构所决定的基座电子压力保持不变，因为温度随密度的增加而降低。边缘压力的增强没有观察到与气体射流，而观察到与高场侧弹丸注射。随着气体射流的增加，基座离子温度也随之降低。随着气体射流密度的增加，约束作用减弱。在未来，重要的是要调查的参数依赖性的基座结构在较宽的实验范围内的背景气体的压力和频率。

项目成果

Study of plasma wall interactions in the long-pulse NB-heated discharges of JT-60U towards steady-state operation

JT-60U 稳态运行长脉冲 NB 加热放电中等离子体壁相互作用的研究

• 发表时间: 2005
• 期刊: Journal of Nuclear Materials 337-339
• 作者: S. Masuzaki;et. al.;H.Takenaga et al.
• 通讯作者: H.Takenaga et al.

Roles of toroidal rotation on heat transport and peripheral structure in H-mode plasmas on JT-60U

JT-60U 上 H 型等离子体中环形旋转对热传输和外围结构的作用

• 发表时间: 2007
• 作者: Mohammad Outokesh;Hitoshi Mimura;Yuichi Niibori;Kouichi Tanaka;三村 均;H.Takenaga;H. Takenaga;H. Mimura;H. Takenaga;Hitoshi Mimura;N. Oyama;M. Outokesh;K. Kamiya;N. Oyama;H. Urano;Mohammad Outokesh;Y. Kamada;大山直幸;神谷健作;浦野創;竹永秀信;H. Takenaga;浦野創;H. Urano
• 通讯作者: H. Urano

JT-60UにおけるHモードペデスタル幅の無次元パラメータ依存性

JT-60U 中 H 模式基座宽度的无量纲参数依赖性

• 发表时间: 2006
• 作者: Mohammad Outokesh;Hitoshi Mimura;Yuichi Niibori;Kouichi Tanaka;三村 均;H.Takenaga;H. Takenaga;H. Mimura;H. Takenaga;Hitoshi Mimura;N. Oyama;M. Outokesh;K. Kamiya;N. Oyama;H. Urano;Mohammad Outokesh;Y. Kamada;大山直幸;神谷健作;浦野創;竹永秀信;H. Takenaga;浦野創;H. Urano;Y.Nakashima;H.Takenaga;H. Takenaga;浦野創
• 通讯作者: 浦野創

Effects of plasma rotation and ripple loss of fast ions on H-mode edge plasmas in JT-60U

JT-60U 中等离子体旋转和快离子纹波损失对 H 模式边缘等离子体的影响

• 发表时间: 2005
• 作者: Mohammad Outokesh;Hitoshi Mimura;Yuichi Niibori;Kouichi Tanaka;三村 均;H.Takenaga;H. Takenaga;H. Mimura;H. Takenaga;Hitoshi Mimura;N. Oyama;M. Outokesh;K. Kamiya;N. Oyama;H. Urano;Mohammad Outokesh;Y. Kamada;大山直幸;神谷健作;浦野創;竹永秀信;H. Takenaga;浦野創;H. Urano;Y.Nakashima;H.Takenaga;H. Takenaga;浦野創;大山直幸;H. Urano;N. Oyama;神谷健作;K. Kamiya;H.Urano;H.Takenaga;N.Oyama;H. Takenaga;H.Urano;H.Takenaga;H. Urano;H. Takenaga;神谷健作;浦野創;K. Kamiya;H. Urano
• 通讯作者: H. Urano

Pedestal conditions for small ELM regimes in tokamaks

• DOI: 10.1088/0741-3335/48/5a/s16
• 发表时间: 2006-05
• 期刊: Plasma Physics and Controlled Fusion
• 影响因子: 2.2
• 作者: N. Oyama;P. Gohil;L. Horton;A. Hubbard;J. Hughes;Y. Kamada;K. Kamiya;A. Leonard;A. Loarte