俘获电子效应对低杂波电流驱动的影响

利用的程序是基于FASTFP开发的RFP准线性Fokker-Planck程序，该程序适用于各种辅助加热和电流驱动的动力学计算.利用开发的编码对低杂波在托卡马克等离子体中的吸收和驱动效率进行了Fokker-Planck计算，考查了环形托卡马克装置的纵横比对波功率沉积和电流驱动效率产生的作用.研究表明，俘获电子效应对低杂波电流驱动的影响与波驱动的功率谱结构有关.俘获电子的平行速度较低，优化的功率谱可以在共振的电子数和俘获电子之间取得折中.俘获电子效应可以使低杂波电流驱动效率减小30%. 关键词： Fokker-Planck方程 俘获电子效应 低杂波电流驱动

Effects of the trapping effect on LHCD in tokamak

A Fokker-Planck study is carried out for tokamak lower hybrid current drive (LHCD)by considering the wave absorption in the presence of trapping effect situation. This Fokker-Planck code is developed based on FASTFP, and is suitable for various auxiliary heating and current drive situations. The energy loss mechanism through anomalous transport is modeled by using a suitable loss term. In the h eating phase, the electron distribution deviates clearly from the Maxwellian, an d this results in nonlinear absorption characteristics. As an electrostatic forc e, the lower hybrid wave makes the trapped electrons untrapped, and the wave los ses its energy,which cuts down the LHCD efficiency 30%.