The neutral beam (NB) fast ion confinement in the Large Helical Device (LHD) is studied for several full field ( ) magnetic configurations by a combination of neutron measurement and simulations. To investigate the NB fast ion confinement, we have performed a series of short-pulse NB injection experiments. The experiment results are analysed by the integrated code TASK3D-a. From this investigation, the effective particle diffusion coefficients of the tangential and perpendicular NBs are approximately and in the standard configuration. It is clarified that the NB fast ion confinement improves when the plasmas are shifted inward. Moreover, it is also found that the simulation, which considers the deuteron dilution effect due to the presence of impurity ions, can describe a neutron emission rate consistent with the measurement.

中文翻译：

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用中子测量和集成码研究大型螺旋装置中的快离子约束

通过中子测量和模拟的组合，研究了大型螺旋装置 (LHD) 中的中性束 (NB) 快速离子约束的几种全场 ( ) 磁性配置。为了研究 NB 快离子限制，我们进行了一系列短脉冲 NB 注入实验。实验结果由集成代码TASK3D-a进行分析。从这项调查中，切向和垂直 NB 的有效粒子扩散系数近似且处于标准配置中。很明显，当等离子体向内移动时，NB 快离子限制得到改善。此外，还发现模拟由于杂质离子的存在而考虑了氘稀释效应，可以描述与测量一致的中子发射率。