Impact of heat deposition profile on global confinement of NBI heated plasmas in the LHD
Impact of heat deposition profile on global confinement of NBI heated plasmas in the LHD
复制标题
热沉积剖面对 LHD 中 NBI 加热等离子体全局限制的影响
DOI：
10.1088/0029-5515/43/8/317
复制
发表时间：
2003
期刊：
影响因子：
3.3
通讯作者：
O. Motojima
中科院分区：
文献类型：
--
作者：
H. Yamada;S. Murakami;K. Yamazaki;O. Kaneko;J. Miyazawa;R. Sakamoto;K. Watanabe;K. Narihara;K. Tanaka;S. Sakakibara;M. Osakabe;B. Peterson;S. Morita;K. Ida;S. Inagaki;S. Masuzaki;T. Morisaki;G. Rewoldt;H. Sugama;N. Nakajima;W. A. Cooper;T. Akiyama;N. Ashikawa;M. Emoto;H. Funaba;P. Goncharov;M. Goto;H. Idei;K. Ikeda;M. Isobe;K. Kawahata;H. Kawazome;K. Khlopenkov;T. Kobuchi;A. Komori;A. Kostrioukov;S. Kubo;R. Kumazawa;Y. Liang;T. Minami;S. Muto;T. Mutoh;Y. Nagayama;Y. Nakamura;H. Nakanishi;Y. Narushima;K. Nishimura;N. Noda;T. Notake;H. Nozato;S. Ohdachi;N. Ohyabu;Y. Oka;T. Ozaki;A. Sagara;T. Saida;K. Saito;M. Sasao;Kuninori Sato;M. Sato;T. Seki;T. Shimozuma;M. Shoji;H. Suzuki;Y. Takeiri;N. Takeuchi;N. Tamura;K. Toi;T. Tokuzawa;Y. Torii;K. Tsumori;Tomo;T. Watari;Y. Xu;I. Yamada;S. Yamamoto;T. Yamamoto;M. Yokoyama;Y. Yoshimura;M. Yoshinuma;T. Mito;K. Itoh;K. Ohkubo;I. Ohtake;T. Satow;S. Sudo;T. Uda;K. Matsuoka;O. Motojima
讨论了大螺旋装置(LHD)中无净电流NBI加热等离子体的能量约束和热输运，重点讨论了密度和功率沉积分布的依赖关系。虽然在LHD中，能量限制时间的表观密度依赖关系在很大的参数范围内被证明，但在特定条件下的高密度区域，这种依赖关系已经被观察到了。由于中性束的离轴排列和浅穿透导致的广泛热沉积降低了整体能量限制，而局部热传输保持了明显的温度依赖性，介于玻姆特性和陀螺-玻姆特性之间。中心热沉积从失去密度依赖的状态趋向于像tau(E)α((N)比bar(E)/p)(0.6)那样的本征密度依赖。由于宽广的热沉积分布而导致的温度分布的加宽与托卡马克实验中广泛观察到的轮廓弹性或刚性的不变性形成了鲜明对比。磁轴内移导致的约束改善在核心区明显，这强调了输运的改善，因为在这种构型下，几何形状不利于NBI的集中加热。边缘压力显然不依赖于磁轴位置。与托卡马克H模不同，边缘压力由传输决定，并可以通过增加加热功率来增加。
Energy confinement and heat transport of net-current-free NBI heated plasmas in the large helical device (LHD) are discussed with emphasis on density and power deposition profile dependences. Although the apparent density dependence of the energy confinement time has been demonstrated in a wide parameter range in LHD, the loss of this dependence has been observed in the high density regime under specific conditions. Broad heat deposition due to off-axis alignment and shallow penetration of neutral beams degrades the global energy confinement while the local heat transport maintains a clear temperature dependence, lying between Bohm and gyro-Bohm characteristics. The central heat deposition tends towards an intrinsic density dependence like tau(E) alpha ((n) over bar (e)/p)(0.6) from the state where density dependence is lost. The broadening of the temperature profile due to the broad heat deposition profile contrasts with the invariant property that has been observed widely as profile resilience or stiffness in tokamak experiments. The confinement improvement as a result of the inward shift of the magnetic axis is obvious in the core region, which emphasizes the improvement of transport because of the geometry being unfavourable for the central heating of NBI in this configuration. The edge pressure, clearly, does not depend on the magnetic axis position. Unlike a tokamak H-mode, the edge pressure is determined by transport and can be increased by increasing the heating power.