权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Optimization of Divertor

偏滤器优化

基本信息

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

项目摘要

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

偏滤器区的粒子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。为了研制一种具有V族金属膜与氢原子相互作用的“超渗透”的偏滤器抽运系统，开展了等离子体膜基础表面物理实验和聚变装置偏滤器区抽氢原理验证实验。在偏滤器区域，对于真空部件，通常可以看到膜表面上的高能离子溅射和杂质（金属和碳）沉积。在基本的等离子体膜实验中研究了这些事件对膜透氢性能的影响。在实验中观察到氢渗透速率的下降，并找到了提高氢渗透速率的方法。另一方面，用铌膜进行氢粒子泵送在世界上尚属首次。 ...更多信息在JFT-2 M托卡马克偏滤器等离子体中发现的。这表明膜泵系统可用于偏滤器区域。因此，我们有可能在前景实现一个膜泵系统或面板泵系统作为偏滤器抽运方法。我们研究了偏滤器等离子体的性质在Heliotron型，大型和小型设备（LHD，Uragan-3 M）。在偏滤器配置中，热量和粒子最终流向偏滤器板。我们发现偏滤器板上的热沉积模式不是上下对称的。对于具有较高RF功率的较小器械（Uragan-3 M），不对称程度较高。这种不对称性随着磁场的反转而反转。这些观察结果解释的直接（非扩散）损失（Bx的B漂移）的离子从限制体积。通过探针测量最后一个封闭表面之外的边缘中的密度和电势波动。由波动测量估计的粒子通量与由粒子平衡估计的粒子通量相当。此外，超过50%的由于波动引起的颗粒损失发生在爆发阶段。少