Mffect of non-Maxwellian distribution on the neoclassical transport and the possibility of transport improvement

近年来，在LHD高Z等离子体中观察到了离子温度的快速升高。在这种等离子体中，强切向注入NBI加热作用于低密度等离子体，束流离子密度变得与背景电子密度相当，因此需要包括Bean离子分布的一致性分析来确定径向电场。用GNET/FIT分析了束流离子输运，用DCOM/NNW分析了新经典输运。结果表明，与热离子相比，切向注入的束流离子在慢化过程中的径向输运很小，慢化束流离子的存在有效地降低了离子净粒子通量。我们还发现，这种净离子粒子通量的降低可以增强LHD中径向电场到电子根的跃迁。

Recently, a rapid increase of ion temperature has been observed in LHD high-Z plasma. In this plasma, the strong tangentially injection NBI heating is applied to a low-density plasma and beam ion density becomes comparable to the background electron density Therefore a consistent analysis including the bean ion distribution is necessary to determine the radial electric field.Effect of tangentially injected beam ions on the radial electric field transition is studied in LHD plasma. The beam ion transport is analyzed by GNET/FIT and the neoclassical transport is by DCOM/NNW. It is found that the radial transport of tangentially injected beam ions during slowing-down is very small compared to that of thermal ions and the net ion particle flux is reduced effectively by the existence of the slowing-down beam ions. Also we found that this reduction of net ion particle flux can enhance the transition of the radial electric field to the electron root in LHD.