环位形下鱼骨模驱动快离子输运的数值模拟研究

Numerical simulation of fast ion transport driven by fishbone in toroidal configuration

考虑包含动理学效应的鱼骨模结构,使用导心轨道程序ORBIT,在磁面坐标下研究了不同的扰动模幅度、频率对快离子再分布的影响,并分析了粒子与扰动发生共振的条件。模拟得出,鱼骨模扰动会使快离子在实空间、相空间中发生再分布,芯部(Ψ_(p)/Ψ_(w)≤0.2,Ψ_(p)为极向磁通,Ψ_(w)为最后一个闭合磁面的磁通)快离子密度下降约20%,中间磁面位置上(0.2≤Ψ_(p)/Ψ_(w)≤0.6)的快离子密度增加约7%;通过扫描频率发现,相空间中快离子的再分布对模式频率敏感,并分析了快离子与鱼骨模扰动共振的条件。

In this work,the influences of the fishbone amplitude and frequency on the fast ion redistribution are investigated.The simulation indicates that the fishbone instability causes serious redistribution of fast ions in both real space and phase space.The fast ion density decreases by~20%in the core(Ψ_(p)/Ψ_(w)≤0.2)and increases~7%at the middle region of magnetic flux(0.2≤Ψ_(p)/Ψ_(w)≤0.6),whereΨ_(p)is the poloidal magnetic flux,andΨ_(w)is the magnetic flux at the last closed flux surface.Furthermore,by parameter scanning,it is found that the redistribution of fast ions is sensitive to the fishbone frequency in the phase space.In addition,the resonance conditions of fast ions and fishbone instability are analyzed.