Recent Advance in LHD Experiment
Recent Advance in LHD Experiment
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LHD实验最新进展
DOI：
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发表时间：
2002
期刊：
影响因子：
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通讯作者：
M. Shoji
中科院分区：
文献类型：
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作者：
O. Motojima;N. Ohyabu;A. Komori;O. Kaneko;H. Yamada;K. Kawahata;Y. Nakamura;K. Ida;T. Akiyama;N. Ashikawa;W. A. Cooper;H. Suzuki;M. Ichimura;N. Tamura;Kenji Tanaka;M. Tanaka;Y. Teramachi;K. Toi;T. Tokuzawa;Y. Tomota;Y. Torii;Y. Miura;H. Kubo;K. Watanabe;T. Watari;Y. Xu;I. Yamada;S. Yamamoto;T. Yamamoto;M. Yokoyama;S. Yoshimura;Y. Yoshimura;T. Nakano;M. Yoshinuma;Y. Kusama;N. Asakura;T. Fujita;T. Fukuda;T. Hatae;S. Higashijima;A. Isayama;Y. Kamada;K. Tsumori;H. Ninomiya;T. Oikawa;N. Oyama;Y. Sakamoto;K. Shinohara;T. Suzuki;A. Ejiri;H. Takenaga;P. Goncharov;K. Ushigusa;T. Hino;Y. Takase;F. Sano;H. Zushi;T. Satow;T. Mito;I. Ohtake;T. Uda;M. Emoto;M. Goto;K. Itoh;K. Ohkubo;S. Sudo;K. Yamazaki;K. Matsuoka;Y. Hamada;M. Fujiwara;N. Ezumi;H. Funaba;A. Fukuyama;H. Idei;K. Ikeda;S. Inagaki;M. Isobe;S. Kado;H. Kawazome;K. Khlopenkov;T. Kobuchi;H. Nakanishi;K. Kondo;A. Kostrioukov;S. Kubo;R. Kumazawa;Y. Liang;J. Lyon;A. Mase;S. Masuzaki;T. Minami;J. Miyazawa;K. Narihara;T. Morisaki;S. Morita;S. Murakami;S. Muto;T. Mutoh;K. Nagaoka;Y. Nagayama;N. Nakajima;K. Nakamura;S. Imagawa;Y. Narushima;K. Nishimura;N. Nishino;N. Noda;T. Notake;H. Nozato;S. Ohdachi;Y. Oka;Y. Takeiri;H. Okada;S. Okamura;M. Osakabe;T. Ozaki;B. Peterson;A. Sagara;T. Saida;K. Saito;S. Sakakibara;M. Sakamoto;N. Takeuchi;R. Sakamoto;M. Sasao;K. Sato;M. Sato;T. Seki;T. Shimozuma;M. Shoji
在LHD实验的头四年里，出现了一些令人鼓舞的结果，其中最重要的是，MHD稳定性和良好的输运是兼容的内移轴位形。在此最佳配置下观察到的能量限制与ISS 95缩放的增强因子为1.5一致。小型日光管器件的约束增强归因于高的边缘温度。我们发现，平均β为3%的等离子体是稳定的，即使在这种配置的Mercier模式和压力驱动的低n模式的理论稳定性条件被违反。在由NBI和ECR加热的低密度放电中，观察到ITB（内部输运势垒）和相关的高中心温度（> 10 keV）。在这些放电中测得的径向电场是正的（电子根），预计将在ITB的形成中发挥关键作用。正电场也被发现抑制离子的热扩散率预测的新古典输运理论。外部施加的岛（n/m=1/1）的宽度被发现减少时，等离子体是碰撞与有限的β和它增加时，等离子体碰撞。在LHD中的ICRF加热是成功的，并且已经检测到少数离子加热的高能量尾部（高达500 keV），表明高能粒子的良好约束。通过测量偏滤器板上的等离子体密度和温度分布，证实了日光管边缘结构所特有的磁力线结构。在ICRF功率为0.4MW的长脉冲（2分钟）放电中，能量约束特性与短脉冲放电基本相同。
In the first four years of LHD experiment, several encouraging results have emerged, the most significant of which is that MHD stability and good transport are compatible in the inward shifted axis configuration. The observed energy confinement at this optimal configuration is consistent with ISS95 scaling with an enhancement factor of 1.5. The confinement enhancement over the smaller heliotron devices is attributed to the high edge temperature. We find that plasma with an average beta of 3 % is stable in this configuration even though the theoretical stability conditions of Mercier modes and pressure driven low n modes are violated. In the low density discharges heated by NBI and ECR heatings, ITB(internal transport barrier) and an associated high central temperature (> 10 keV) are seen. The radial electric field measured in these discharges is positive (electron root) and expected to play a key role in the formation of the ITB. The positive electric field is also found to suppress the ion thermal diffusivity as predicted by neoclassical transport theory. The width of the externally imposed island (n/m=1/1) is found to decrease when the plasma is collisionless with finite beta and it increases when the plasma is collisional. The ICRF heating in LHD is successful and a high energy tail ( up to 500keV) has been detected for minority ion heating, demonstrating good confinement of the high energy particles. The magnetic field line structure unique to the heliotron edge configuration is confirmed by measuring the plasma density and temperature profiles on the divertor plate. A long pulse (2minute) discharge with an ICRF power of 0.4 MW has been demonstrated and energy confinement characteristics are almost the same as those in short pulse discharges.