Control of edge electric field by fast neutral beam injection

(1)We对快离子轨道和径向电场的模拟程序进行了修改，并计算了中大型托卡马克装置中快中性束注入（NBI）对径向电场的影响。（1）得到了两种径向离子损失（直接轨道损失和电荷交换损失，以及由环形NBI引起的径向动量损失），并且已经表明大量的径向离子损失是由边缘处的局部NBI产生的。(2)径向电场随着NBI的变化而变化，以维持径向双极条件。结果表明，50 V/cm的径向电场是由约100 kW的局域NBI引起的。(3)在今后的计算中，应考虑实际的输运模型，如非正常输运。(2)It结果表明，在100 kHz频率范围内，交流限幅器偏压实验可以产生约30 V/cm的振荡径向电场（Er）。附加的振荡极向电场（Ep）由振荡Er产生。这种振荡的Ep可以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.