Characterization and operational regime of high density plasmas with internal diffusion barrier observed in the Large Helical Device
Characterization and operational regime of high density plasmas with internal diffusion barrier observed in the Large Helical Device
复制标题
DOI：
10.1088/0741-3335/49/12b/s46
复制
发表时间：
2007-12
影响因子：
2.2
通讯作者：
H. Yamada;R. Sakamoto;J. Miyazawa;M. Kobayashi;T. Morisaki;S. Masuzaki;S. Ohdachi;M. Goto;K. Ida;S. Sakakibara;K. Tanaka;N. Ashikawa;K. Itoh;S. Morita;Y. Nagayama;Y. Narushima;B. Peterson;M. Shoji;C. Suzuki;Y. Suzuki;T. Tokuzawa;K. Watanabe;I. Yamada;M. Yokoyama;S. Yoshimura;M. Yoshinuma;S. Imagawa;O. Kaneko;K. Kawahata;T. Mutoh;N. Ohyabu;A. Komori;O. Motojima
中科院分区：
文献类型：
--
作者：
H. Yamada;R. Sakamoto;J. Miyazawa;M. Kobayashi;T. Morisaki;S. Masuzaki;S. Ohdachi;M. Goto;K. Ida;S. Sakakibara;K. Tanaka;N. Ashikawa;K. Itoh;S. Morita;Y. Nagayama;Y. Narushima;B. Peterson;M. Shoji;C. Suzuki;Y. Suzuki;T. Tokuzawa;K. Watanabe;I. Yamada;M. Yokoyama;S. Yoshimura;M. Yoshinuma;S. Imagawa;O. Kaneko;K. Kawahata;T. Mutoh;N. Ohyabu;A. Komori;O. Motojima
具有内部扩散势垒 (IDB) 的高密度状态已扩展到大型螺旋装置 (LHD) 中的螺旋偏滤器 (HD) 配置。为了形成 IDB，必须避免中性压力的局部增强，这与使用具有高效主动泵送功能的局部岛偏滤器 (LID) 的早期工作一致。中心压力达到大气压的1.3倍，其中ne(0) = 6 × 1020 m−3 和Te(0) = 660 eV。具有 IDB 的等离子体位于平台碰撞区。尽管存在负径向电场，但在整个放电过程中并未观察到显着的杂质效应。使用 HD 的 IDB 在等离子体中观察到中心压力限制事件。在这个被称为核心密度崩溃（CDC）的事件中，粒子在数百微秒的时间尺度内从核心中被冲出。通过垂直伸长 (κ) 抑制沙夫拉诺夫位移可有效减轻 CDC。当 κ = 1.2 时，中心 β 值在 1 T 时增加至 6.6%。
A high density regime with an internal diffusion barrier (IDB) has been extended to the helical divertor (HD) configuration in the Large Helical Device (LHD). Avoidance of the local enhancement of neutral pressure is necessary to enable IDB formation, which is consistent with earlier works by using the Local Island Divertor (LID) with efficient active pumping. The central pressure reached 1.3 times atmospheric pressure, where ne(0) = 6 × 1020 m−3 and Te(0) = 660 eV. The plasmas with an IDB are located in the plateau collisionality regime. The significant impurity effect has not been observed throughout the discharges in spite of the existence of a negative radial electric field. A central pressure limiting event is observed in the plasmas with an IDB using the HD. During this event which is referred to as the core density collapse (CDC), particles are flushed out from the core on the time scale of a few hundreds of microseconds. The suppression of the Shafranov shift by vertical elongation (κ) is effective to mitigate CDC. At κ = 1.2, the central β value is increased up to 6.6% at 1 T.