The Research And The Correction Of Guiding-center Motion Simulation

The research is based on the theory of guiding-center motion and a code developed by Dr. Xiao Xiaotao for charged particle's guiding-center orbit under tokamak configuration which derived from a canonical equation. A more efficient way to build up the physical functions such as magnetic field has been obtained.The Discrete Fourier Transform is applied to replace Cubic Spline Interpolation and B spline Interpolation method in the calculation of the Guiding-Center's Trajectory. This method does not only have a higher accuracy than Cubic Spline Interpolation but have some advantages which facilitates the calculations in Tearing Mode. The merits of the new method are as followed : It naturally holds the property of symmetrical due to the cosine as base function. And The Derivative for 3rd order or above can be easily obtained from Trigonometric series . Moreover, the effect of some incorrect data will be reduced to the minimal limit.Although it is practical to apply FFT into the calculation of Guiding-center motions, there still is the phenomenon of Frequency overlapping resulted from Sampling effect, which sometimes may hamper the application of FFT. Hence DFT is more desirable to get an accurate result.