Equilibrium Spline Interface (ESI) for magnetic confinement codes

A compact and comprehensive interface between magneto-hydrodynamic (MHD) equilibrium codes and gyro-kinetic, particle orbit, MHD stability, and transport codes is presented. Its irreducible set of equilibrium data consists of three (in the 2-D case with occasionally one extra in the 3-D case) functions of coordinates and four 1-D radial profiles together with their first and mixed derivatives. The C reconstruction routines, accessible also from FORTRAN, allow the calculation of basis functions and their first derivatives at any position inside the plasma and in its vicinity. After this all vector fields and geometric coefficients, required for the above mentioned types of codes, can be calculated using only algebraic operations with no further interpolation or differentiation.

本文提出一种紧凑且通用的接口，可连接磁流体动力学（magneto-hydrodynamic, MHD）平衡代码与回旋动力学（gyro-kinetic）、粒子轨道（particle orbit）、MHD稳定性及输运代码。其不可约平衡数据集包含两类构成：二维情形下为3个坐标相关函数与4个一维径向分布函数，连同其一阶偏导数与混合偏导数；三维情形下则在此基础上偶尔额外增加1个此类函数。该接口附带可通过Fortran语言调用的C语言重构例程，能够计算等离子体内部及其邻近区域任意位置处的基函数及其一阶导数。完成上述步骤后，前述各类代码所需的全部矢量场与几何系数，仅需通过代数运算即可求得，无需再进行额外的插值或微分操作。