Abstract:

For simplifying the calculation the magnetic distribution on tokamak, some two-dimensional analytic models including the effect of the iron core were established, such as the infinite long iron core model and the spool model. The assumptions of these two-dimensional analytic models lead to different results with the actual magnetic field due to the distinctive boundary condition. In order to accurately calculate the three-dimensional magnetic field distribution in the tokamak with iron core, a three-dimensional numerical finite element model was established based on J-TEXT tokamak. In two conditions, where the total toroidal current is nonzero or zero respectively, more comparison were carried out between the derived results of two-dimensional models and the results at different toroidal positions in three-dimensional models. Furthermore, the toroidal asymmetry of the magnetic field distribution of the three-dimensional model of tokamak with iron core was investigated. The results indicate that the three-dimensional construction of iron core causes the toroidal asymmetric poloidal magnetic field and the difference between the two- and three-dimensional models in the condition with total current of nonzero. However, in the condition with total current of zero, the intensity of toroidal asymmetric is reduced and the difference between the two- and three-dimensional models is smaller.

Key words: Tokamak, Iron core, Poloidal magnetic field

摘要：

为方便计算托卡马克磁场分布，建立了一些二维解析铁芯模型。由于前提假设的不同而给磁场分布的计算带来了不同的边界条件，因而得到的磁场分布计算结果与实际情况有所偏差。为了获得铁芯托卡马克的极向磁场三维分布，建立了带铁芯的极向磁场线圈三维数值模型，计算铁芯托卡马克的三维磁场，与不同铁芯模型的磁场计算结果进行比较，并且研究铁芯托卡马克的三维磁场的极向分量在环向上的不对称性。

关键词: 托卡马克, 铁芯, 极向磁场