中型tokamak中快离子的约束

Confinement of fast ions in east tokamak

利用三个运动常数发展了导心轨道程序GCORBIT.该程序在计算轴对称tokamak中带电粒子导心轨道的同时,也考虑了纵场纹波和螺距角散射的效应.GCORBIT可以用来计算轴对称tokamak中的导心轨道,计算速度空间的损失区,计算快离子的损失份额.与已有的工作相比,GCORBIT计算出的速度空间损失区包括了多种效应:偏滤器位形中的非闭合轨道、由于导心轨道与第一壁相交引起的首次轨道损失、纵场纹波局部磁阱俘获、纹波随机扩散以及速度空间不连续约束区导致的螺距角散射效应增强.GCORBIT程序已被用于分析“先进超导托卡马克实验装置”(experimental advanced superconductingtokamak,EAST)tokamak中快离子的约束.并讨论其中的某些数值计算结果.

The three well-known parameters of motion （magnetic momentum, energy and canonical toroidal momentum） are utilized to develop a guiding center orbit code, GCORBIT. The effect of poroidal field ripple and toroidal angle scatter is considered in the GCORBIT. It is applied to compute guiding center orbit of charged particle in axisymmetric tokamak, the loss region of velocity space and the loss fraction of fast ions. To compare achieved results, the loss region of velocity space by GCORBIT includes many effects： non-closed orbit of divertor, first orbit loss by guiding-center orbit being non-closed or intersecting with any material limiters, trapping by the poroidal field ripple in local magnetic wells, ripple random diffusion and toroidal angle scatter enabled by velocity space discontinuous confinement region. The GCORBIT is now being used to analyze the confinement of fast ions in EAST Tokamak. Our numerical calculations are focused on the loss of fast ions.