Control of edge electric field by fast neutral beam injection

(1)修改了快离子轨道和径向电场的模拟代码，计算了中大型托卡马克中快中子束注入（NBI）修正后的径向电场。得到的结果是；(1)我们得到了两种径向离子损失（直接轨道损失和电荷交换损失，以及环形NBI引起的径向动量损失），并表明大量的径向离子损失是由边缘局部化的NBI产生的。(2)径向电场随NBI变化，维持径向双极性状态。(3)在今后的计算中，必须考虑实际输运模型，如异常输运等，对代码进行修改。(2)在100 kHz的交流限幅器偏置实验中，可产生约30 V/cm的振荡径向电场（Er）。额外的振荡极向电场（Ep）是由振荡的Er产生的。这种振荡电位有可能改变粒子的径向输运。

(1)We have modified the simulation codes for fast ion orbit and radial electric field and calculated the radial electric field modified by fast neutral beam injection(NBI) in medium and large size tokamaks.Results obtained are;(1) We have obtained two kinds of radial ion losses(direct orbit loss and charge exchange loss, and radial momentum loss induced by toroidal NBI) and have shown that a large amount of radial ion losses are generated by localized NBI at the edge.(2) Radial electric field changes with NBI to maintain the radial ambipolar condition. It is shown that the radial electric field of 50 V/cm is induced by localized NBI of about 100 kW.(3) In future, a modification of the code that the realistic transport model ,such as the extraordinary transport must be taken account in the present calculation.(2)It is shown that the oscillating radial electric field(Er) of about 30 V/cm can be generated by the AC limiter bias experiment up to 100 kHz. The additional oscillating poloidal electric field(Ep) is generated by the oscillating Er. This oscillating Ep is possible to modify the radial particle transport.