Pellet Developments and Plasma Diagnostics

颗粒开发和等离子体诊断

基本信息

批准号：
11210207
负责人：
SUDO Shigeru
金额：
$ 12.99万
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

Knowledge of plasma transport is a key for achieving high performance plasmas confinement in fusion devices. Injection of impurity cores inserted into polysterene capsules gives a local plasma perturbation, however, some extra impurities such as carbon contained in the capsule appear. Thus, it is proposed to use pellets made from ice of bulk plasmas components, i.e. hydrogen isotopes, as capsules. When such pellet enters the plasma, the outer solid hydrogen layer is ablated first, keeping the impurity core from ablation up to the plasma column axis. This results in an intensive ablation of the core providing the small localization of the deposited tracer ions. Experimentally observed evolution of the impurity ions gives data for analytical calculation of diffusion coefficient of the bulk plasmas. Thus, a new injector for making solid hydrogen pellets around impurity cores has been developed for plasma transport study in Large Helical Device. A new technique has been employed for automatic loading carbon or polysterene cores of 0.2 mm diameter from a gun magazine to a light-gas gun barrel. The injector is equipped with a cryorefrigerator and is able to form a 3.2 mm long and 3 mm diameter cylindrical solid hydrogen pellet at 7-8 K with an impurity core in its center within 6 minutes and to inject it in the light-gas gun up to 1 km/s. The reliability and technology of pellet formation and acceleration in the injector was sufficient and efficient. A differential pumping system with a guide tube for pellet transportation to the plasma and cutting off a propellant gas has been designed and is being installed between the injector and LHD.

了解等离子体传输是在聚变装置中实现高性能等离子体限制的关键。将杂质核注入聚苯乙烯胶囊中会产生局部等离子体扰动，但是会出现一些额外的杂质，例如胶囊中含有的碳。因此，建议使用由大量等离子体成分（即氢同位素）的冰制成的丸粒作为胶囊。当这种颗粒进入等离子体时，外部固体氢层首先被烧蚀，从而防止杂质核心被烧蚀到等离子体柱轴。这导致核心的强烈烧蚀，提供了沉积示踪离子的小定位。实验观察到的杂质离子的演化为体等离子体扩散系数的分析计算提供了数据。因此，开发了一种用于在杂质核心周围制造固体氢颗粒的新型注射器，用于大型螺旋装置中的等离子体传输研究。采用新技术将直径为 0.2 毫米的碳或聚苯乙烯芯从枪弹匣自动装载到轻气体枪管中。该注射器配备低温制冷机，能够在7-8 K下于6分钟内形成长3.2毫米、直径3毫米的圆柱形固体氢丸，其中心为杂质核，并注射到轻气枪中至 1 公里/秒。注射器中颗粒形成和加速的可靠性和技术是充分且高效的。已经设计了一个差动泵系统，该系统带有导管，用于将颗粒输送到等离子体并切断推进剂气体，并将其安装在喷射器和 LHD 之间。