共查询到16条相似文献,搜索用时 140 毫秒
1.
在EAST上通过分析剩余环电压与低杂波功率之间的关系,计算得到了低杂波电流驱动效率。采用归一化功率,即功率对等离子体电流、电子密度、等离子体大半径以及有效电荷数归一化,将所有数据绘制在同一曲线中,这样可以得到不同等离子体参数下的低杂波电流驱动效率。实验得到低杂波电流驱动效率η0=(0.5~1.3)×1019 A.m-2.W-1,在等离子体电流Ip=277kA、低杂波功率PLH=681kW条件下,实验得到长达3s的低杂波全波驱动。 相似文献
2.
在EAST上通过分析剩余环电压与低杂波功率之间的关系,计算得到了低杂波电流驱动效率。采用归一化功率,即功率对等离子体电流、电子密度、等离子体大半径以及有效电荷数归一化,将所有数据绘制在同一曲线中,这样可以得到不同等离子体参数下的低杂波电流驱动效率。实验得到低杂波电流驱动效率η0=(0.5~1.3)×1019 A.m-2.W-1,在等离子体电流Ip=277kA、低杂波功率PLH=681kW条件下,实验得到长达3s的低杂波全波驱动。 相似文献
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为研究高参数等离子体的低杂波可近性,基于HL-3装置设计了一套位于强场侧的低杂波天线。利用ALOHA代码对强场侧的天线进行模拟分析,针对只有一个单元的PAM天线,分别对其子波导数量、有源/无源子波导的高度、宽度和壁厚等参数进行模拟,得到了天线的最佳结构和尺寸。最终优化后的天线发射参数为:波谱中心的平行折射率N|为2.25,天线的反射系数小于2%,方向性系数大于0.59。 相似文献
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秦运文 《核聚变与等离子体物理》1996,(4)
在一些HL-1托卡马克的低杂波电流驱动(LHCD)实验中,驱动效率对低杂波注入功率和等离子体电子密度等参数的依赖关系很分散。分析表明,其可能原因是驱动电流的计算不够精确,携带电流的快电子的相当部分逃离等离子体后损失到孔栏或真空室壁上以及放电的重复性差等。本文对这些问题进行了仔细的讨论 相似文献
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秦运文 《核聚变与等离子体物理》1996,16(4):1-6
在一些HL-1托卡马克的低杂波电流驱动实验中,驱动效率对低杂波注入功率和等离子体电子密度等参数的依赖关系很分散。分析表明,其可能原因是驱动电流的计算不够精确,携带电流的快是电子相当的部分逃离等体后损失到也栏或真空室壁上,以及放电的重复性差等。本文对这些问题进行了仔细的讨论。 相似文献
6.
在HT-7超导托卡马克装置上利用低杂波电流驱动有效地控制了等离子体电流分布,并使等离子体约束性能改善。数值模拟与硬X射线测量结果均表明,低杂波的发射功率谱、纵场和等离子体密度对改变等离子体电流分布有明显的影响。在优化低杂波电流驱动实验参数的条件下,等离子体密度、温度分布发生了理想的变化。在电子和离子温度分布上出现了内部输运垒,同时等离子体的能量约束时间和粒子约束时间均有提高。 相似文献
7.
应用改进后的低杂波电流驱动程序对EAST进行了低杂波电流驱动的数值模拟。通过模拟发现,波注入位置、功率谱、等离子体温度和密度对低杂波的功率沉积和电流驱动剖面分布有很大影响。通过选取合适的低杂波功率谱、等离子体温度和密度,可以实现对其功率沉积和电流驱动剖面分布的控制。 相似文献
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本文利用较简单的计算模型计算低杂波沿射线轨迹的能量沉积和电流分布。结果表明,当等离子体中心电于温度不太高(Te<1keV)时,边缘冷等离子体区电子-离子碰撞吸收的能量占相当大的比例,因此电流驱动效率较低。提高中心和边缘电子温度,将较大幅度地增加低杂波电流驱动效率,从而可解释为什么在小托卡马克中低杂波电流驱动效率比在大、中型托卡马克中小得多。 相似文献
10.
应用改进后的低杂波电流驱动程序对EAST进行了低杂波电流驱动的数值模拟。通过模拟发现,波注入位置、功率谱、等离子体温度和密度对低杂波的功率沉积和电流驱动剖面分布有很大影响。通过选取合适的低杂波功率谱、等离子体温度和密度,可以实现对其功率沉积和电流驱动剖面分布的控制。 相似文献
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Experimental characteristics of a lower hybrid wave multi-junction coupler in the HT-7 tokamak 总被引:1,自引:0,他引:1 下载免费PDF全文
A phase-controlled lower hybrid wave (LHW) multi-junction (MJ) coupler
(3(rows)×(columns)× (subwaveguides)) has been developed in the
HT-7 tokamak. Simulations show that it is more effective for driving plasma current
than an ordinary phase-controlled LHW antenna (3(rows)×12(columns))
(traditional coupler). The plasma--wave coupling experiments show that the
reflection coefficient (RC) is below 10%, implying that the MJ grill can launch
the wave into the plasma effectively. The effect of power spectrum launched by the
MJ coupler on RC indicates that an optimal condition is requisite for a better
coupling in the lower hybrid current drive (LHCD) experiments. Studies indicate that
the drive efficiency of the MJ antenna is higher than that of the traditional one,
which is mainly ascribed to the discrepancy in impurity concentration, plasma
temperature, and spectrum directivity. An improved confinement with an electron
internal transport barrier is obtained by LHCD. The analysis shows that the
modified negative (low) magnetic shear and the change of radial electric field
profile due to LHCD are possible factors responsible for the eITB formation. 相似文献
13.
Optimized calculation of the synergy conditions between electron cyclotron current drive and lower hybrid current drive on EAST 下载免费PDF全文
The optimized synergy conditions between electron cyclotron current drive(ECCD) and lower hybrid current drive(LHCD) with normal parameters of the EAST tokamak are studied by using the C3PO/LUKE code based on the understanding of the synergy mechanisms so as to obtain a higher synergistic current and provide theoretical reference for the synergistic effect in the EAST experiment. The dependences of the synergistic effect on the parameters of two waves(lower hybrid wave(LHW) and electron cyclotron wave(ECW)), including the radial position of the power deposition, the power value of the LH and EC waves, and the parallel refractive indices of the LHW(N) are presented and discussed. 相似文献
14.
W.Y. Zhang Y.D. Li X. Gao S.Y. Lin Q. Zang Y.X. Jie X.D. Zhang J. Li HT- Teams 《Physics letters. A》2010,374(34):3508-492
An experimental study of medium and high-k density fluctuations has been performed during low hybrid current drive (LHCD) in the HT-7 tokamak. Two series of plasma discharges in different plasma current with a limiter configuration were conducted in which the injected LHW power was gradually increased. The fluctuation level of the mode in channel kθ=12 cm−1 and kθ=20 cm−1 is related to the q profile, and the normalized frequency spectrum is found to be independent of the LHW power. 相似文献
15.
讨论了低杂波电流驱动(LHCD)实验中电流驱动效率、电流分布控制与等离子体参数和入射波谱的关系,以及波的可近性对确定功率沉积分布的作用。讨论了控制电流密度分布的方法及在HL-2A装置上实现中心负剪切位形的可能性。 相似文献
16.
���������������� �������Ʋ��������¾� 《核聚变与等离子体物理》2013,33(3):214-218
The synergy current drive by combining electron cyclotron wave (ECW) with lower hybrid wave (LHW) can be used to either increase the noninductive current drive efficiency or shape the plasma current profile. In this paper, the synergy current drive by ECW and LHW is studied with numerical simulation. The nonlinear relationship between the wave powers and the synergy current of ECW and LHW is revealed. When the LHW power is small, the synergy current reduces as the ECW power increases, and the synergy current is even reduced to lower than zero, which is referred as negative synergy in the this context. Research shows that the mechanism of the negative synergy is the peaking effect of LHW power profile and the trapped electrons effect. The present research is helpful for understanding the physics of synergy between electron cyclotron current drive and lower hybrid current drive, it can also instruct the design of experiments. 相似文献