Optimization of Divertor

偏滤器优化

• 批准号: 11210205
• 负责人: OHYABU Nobuyoshi
• 金额: $ 10.94万
• 依托单位: National Institute for Fusion Science
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research on Priority Areas
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2004
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-11210205/
• 关键词: Divertor pumping; Hydrogen superpermeation; Membrane; Ion sputtering; Impurity deposition; Helical Divertor; Heliotron Device; GradB drift; Uragan-3M; Bx∇Bドリフト; ダイバータ粒子束の非対称性; V属金属; 水素透過・吸蔵; ニオブ; バナジウム; トロイダB×▽Bドリフト; 高速イオンの直接損失; 水素排気; 超透

Particle control in divertor region is of great importance for production and confinement of high performance plasma in magnetic confinement device. In order to develop a new type of divertor pumping system with a "superpermeation", which is the interaction between V-group metal membranes and hydrogen atoms, we carried out plasma-membrane experiments on basic surface physics and proof-of-principle experiments on hydrogen pumping in divertor region in fusion devices. In the divertor region, high-energy ion sputtering and impurity (metal and carbon) deposition on the membrane surface can be usually seen for vacuum components. The influence of such events on hydrogen permeation performance of membrane is investigated in the basic plasma-membrane experiments. The degradation of hydrogen permeation rate is observed and the method to improve the permeation rate is also found in the experiments. On the other hand, hydrogen particle pumping with a Nb membrane has been first time in the world d … More emonstrated in the divertor plasma in the JFT-2M tokamak. This suggests that the membrane pumping system is available in the divertor region. As a result, we have a possibility in prospect to realize a membrane pumping system or a panel pumping system as a divertor pumping method.We have studied properties of divertor plasma in the Heliotron type, large and small devices (LHD, Uragan-3M). In the divertor configuration, the heat and particle flows eventually on to the divertor plates. We find that the heat deposition patterns on the divertor plates are not up-down symmetric. Degree of the asymmetry is higher for the smaller device (Uragan-3M) with higher RF power. The asymmetry is reversed with reversal of the magnetic field. These observations are explained by the direct (non-diffusive) loss (the Bx∇B drift) of the ion from the confinement volume. The density and potential fluctuations in the edge beyond the last closed surface are measured by the probes. The particle flux estimated by the fluctuation measurement is comparable to that evaluated from the particle balance. Furthermore more than 50 % of the particle loss due to the fluctuations take place during the burst phase. Less

偏滤器区域的颗粒控制对于磁约束装置中高性能等离子体的产生和约束具有重要意义，为了开发一种具有“超渗透”功能的新型偏滤器泵送系统，即V族金属膜与磁力膜之间的相互作用。氢原子，我们进行了基本表面物理的等离子体膜实验以及聚变装置偏滤器区域中氢泵浦的原理验证实验。对于真空元件，通常可以看到膜表面上的杂质（金属和碳）沉积，在基本的等离子体膜实验中研究了此类事件对膜的氢渗透性能的影响，并观察了氢渗透率的下降。实验中还发现了提高渗透率的方法。另一方面，在JFT-2M的偏滤器等离子体中，使用铌膜泵送氢粒子在世界上尚属首次。这表明膜泵浦系统可用于偏滤器区域。因此，我们有可能实现膜泵浦系统或面板泵浦系统作为偏滤器泵浦方法。我们研究了偏滤器等离子体的特性。在 Heliotron 类型、大型和小型设备（LHD、Uragan-3M）中，在偏滤器配置中，热量和粒子最终流到偏滤器板上，我们发现偏滤器板上的热沉积模式不是上下的。具有较高射频功率的较小设备 (Uragan-3M) 的不对称程度较高，这些观察结果可以通过直接（非扩散）损耗 (Bx∇) 来解释。离子从限制体积中的密度和电势波动由探针测量。通过波动测量估计的粒子通量与根据粒子通量评估的粒子通量相当。甚至超过 50% 的颗粒损失是在爆发阶段发生的。

项目成果

N. Ohyabu, et al.: "Active Control of Hydrogen Recycling by the Permeation and Absorption Techniques"Proc. of International Workshop on Hydrogen Recycling at Plasma Facing Materials. (to be published).

N. Ohyabu 等人：“通过渗透和吸收技术主动控制氢回收”Proc。

Hydrogen Release through Metallic Surface : the Role of Sputtering and Impurity Dynamics

通过金属表面释放氢：溅射和杂质动力学的作用

• 发表时间: 2004
• 期刊: Physica Scripta T108
• 作者: Nakajima;H.;et al.;A.I Livshits
• 通讯作者: A.I Livshits

E.L.Sorokovoy: "Density and potential fluctuations in the edge plasma of the Uragan-3M torsatron"Problems of Atomic Science and Technology, Series Plasma Physics. 5. 6 (2002)

E.L.Sorokovoy：“Uragan-3M 托萨管边缘等离子体的密度和电位波动”原子科学与技术问题，系列等离子体物理。

S.Masuzaki: "Review of initial experimental results of the PSI studies in the Large Helical Device"Journal of Nuclear Materials. 290-293巻. 12-16 (2001)

S.Masuzaki：“大型螺旋装置 PSI 研究的初步实验结果回顾”，核材料杂志，第 290-293 卷（2001 年）。

DIVERTOR FLOW AND PARTICLE LOSS BEHAVIORS IN SPONTANEOUS CHANGE OF CONFINEMENT STATE IN THE URAGAN-3M TORSATRON

URAGAN-3M TorSATRON 约束状态自发变化中的转向器流动和颗粒损失行为

• 发表时间: 2005
• 期刊: Problems of Atomic Science and Technology, Series : Plasma Physics (11),No.2
• 作者: V.V.Chechkin;et al.
• 通讯作者: et al.