A strong relationship between the fishbone instability and internal transport barrier (ITB) formation has been found on the Experimental Advanced Superconducting Tokamak (EAST) in high β N ELMy H-mode discharges. ITB formation always appears after the fishbone instability, and the fishbone disappears when the ITB grows to a certain extent. Hybrid simulations with the global kinetic-magnetohydrodynamic (MHD) code M3D-K have been carried out to investigate the linear stability and non-linear dynamics of beam-driven fishbone instabilities in these shots. The simulation results show that the fishbone instability absorbs the energy of the fast ions and changes the distribution function of the fast ions, leading to the accumulation of fast ions near the ITB, which might eventually assist in the formation of the ITB. The q = 1 surface disappearance caused by the bootstrap current generated by the steep pressure gradient in the ITB region has been con...

中文翻译：

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EAST托卡马克鱼骨与ITB形成关系的实验观察与模拟分析。

在高βN ELMy H型放电的实验高级超导托卡马克（EAST）上，已经发现鱼骨不稳定性与内部运输屏障（ITB）形成之间的密切关系。ITB的形成总是在鱼骨不稳定之后出现，而当ITB增长到一定程度时，鱼骨消失。进行了具有全局动磁磁流体动力学（MHD）代码M3D-K的混合模拟，以研究这些击中光束驱动鱼骨不稳定性的线性稳定性和非线性动力学。仿真结果表明，鱼骨的不稳定性吸收了快离子的能量并改变了快离子的分布功能，导致快离子在ITB附近积累，最终可能有助于ITB的形成。