Engineering prospects of negative-ion-based neutral beam injection system from high power operation for the large helical device
Engineering prospects of negative-ion-based neutral beam injection system from high power operation for the large helical device
复制标题
大型螺旋装置高功率负离子中性束注入系统的工程前景
DOI：
10.1088/0029-5515/43/8/309
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发表时间：
2002
期刊：
影响因子：
3.3
通讯作者：
M. Sato
中科院分区：
文献类型：
--
作者：
O. Kaneko;Y. Takeiri;K. Tsumori;Y. Oka;M. Osakabe;K. Ikeda;K. Nagaoka;T. Kawamoto;E. Asano;M. Sato
回顾了大螺旋装置（LHD）上负离子中性束注入器（N-NBI）系统5年来的运行情况，并根据这些经验讨论了负离子技术在未来螺旋聚变堆中的应用前景。N-NBI系统是基于NIFS的研发成果设计和构建的。使用三条光束线，总端口通过注入功率为10.3兆瓦的2秒已实现。每条束线都获得了几乎相同的性能：~3.5 MW的端口通过功率，氢的束能量为~165 keV，这对应于每个离子源的平均负离子电流密度为25 mA cm−2。最近修改的加速器中的一个光束线是非常成功的，以增加光束能量高达180千电子伏和端口通过功率，4.4兆瓦。在稳态LHD操作下也追求长脉冲注入加热，并且通过一个离子源实现了0.1MW的110 s，并且通过两个离子源（一个束线）实现了0.5MW的80 s。这些事实表明，负离子技术已经建立到与常规正离子系统相同的功率水平。本文介绍了为获得这些成功结果所需的几项技术改进，并阐明了限制目前性能的问题。最近的R&D，以解决这些问题的一些结果。
The five-year operation of the negative-ion-based neutral beam injector (N-NBI) system on the large helical device (LHD) is reviewed, and the prospects of negative-ion technology for applying it to future helical fusion reactors are discussed from these experiences. The N-NBI system was designed and constructed based on the results of R&D at NIFS. Using three beamlines, the total port-through injection power of 10.3 MW for 2 s has been achieved. Each beamline attained almost the same performance: ~3.5 MW of the port-through power with the beam energy of ~165 keV for hydrogen, which corresponds to the averaged negative ion current density of 25 mA cm−2 from each ion source. Recent modification of accelerators in one of the beamlines was very successful to increase beam energy up to 180 keV and port-through power, 4.4 MW. Long pulse injection heating was also pursued under the steady state LHD operation, and 110 s for 0.1 MW by one ion source, and 80 s for 0.5 MW by two ion sources (one beamline) were achieved. These facts show that the negative ion technology has been established to the same power level of conventional positive ion systems. Several technical improvements needed for obtaining these successful results are described, and the problems that limit the present performance are clarified. Some results of recent R&D to solve these problems are shown.