Construction and Operation of an Internal Coil Device, RT-1, with a High-Temperature Superconductor
Construction and Operation of an Internal Coil Device, RT-1, with a High-Temperature Superconductor
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DOI：
10.1585/pfr.4.020
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发表时间：
2009-05
影响因子：
0.8
通讯作者：
Y. Ogawa;Z. Yoshida;J. Morikawa;H. Saito;S. Watanabe;Y. Yano;S. Mizumaki;T. Tosaka
中科院分区：
文献类型：
--
作者：
Y. Ogawa;Z. Yoshida;J. Morikawa;H. Saito;S. Watanabe;Y. Yano;S. Mizumaki;T. Tosaka
基于新的弛豫理论，构建了一个名为Ring Trap-1 （RT-1）的内部线圈装置，以探索高β等离子体的创新概念。RT-1的内部线圈采用高温超导体（HTS） Bi-2223磁带。用G-M电冰箱提供的氦气将线圈冷却到20 K，并使用外部电源充电至250 kA的磁动势。针对这些冷却和充电方法，我们开发了一些创新技术，如可拆卸转移管系统，持续电流开关，可拆卸电极等。此外，我们非常关注HTS胶带在制造内部线圈过程中的劣化问题。因此，我们已经证明，在8小时内，内部线圈的持续电流衰减约为1%。内部线圈被位于真空容器上部的悬浮线圈提升。通过对悬浮线圈电流的调节，对激光传感器监测的线圈位置进行反馈控制。几个小时的稳定悬浮已经在各种等离子体实验中得到了证明。
An internal coil device called Ring Trap-1 (RT-1) has been constructed to explore an innovative concept for a high-beta plasma based on a new relaxation theory. A high-temperature superconductor (HTS) Bi-2223 tape is employed for the internal coil of RT-1. The coil is cooled to 20 K with helium gas supplied by G-M refrigerators, and charged to a magnetomotive force of 250 kA using an external power supply. For these cooling and charging methods, we have developed several innovative techniques such as a demountable transfer tube system, persistent current switch, detachable electrode, and others. In addition, we have paid much attention to the deterioration of the HTS tape during the fabrication of the internal coil. As a result, we have demonstrated that the decay of the persistent current of the internal coil is ∼1% during 8 h. The internal coil is lifted with a levitation coil located at the upper region of the vacuum vessel. The coil position monitored with laser sensors is feedback controlled through the regulation of the levitation coil current. Stable levitation for a few hours has been demonstrated for various plasma experiments.