COBRA: An Optimized Code for Fast Analysis of Ideal Ballooning Stability of Three-Dimensional Magnetic Equilibria
✍ Scribed by R. Sanchez; S.P. Hirshman; J.C. Whitson; A.S. Ware
- Book ID
- 102586806
- Publisher
- Elsevier Science
- Year
- 2000
- Tongue
- English
- Weight
- 89 KB
- Volume
- 161
- Category
- Article
- ISSN
- 0021-9991
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✦ Synopsis
A new, fast, and accurate numerical algorithm to assess stability against ideal ballooning modes in general three-dimensional magnetic configurations of interest to controlled thermonuclear fusion is described. The code for ballooning rapid analysis (COBRA) performs this assessment by solving an eigenvalue problem in the form of a linear second-order ordinary differential equation along magnetic field lines in the configuration. An initial approximation for the eigenvalue is obtained from a fast second order matrix method. In COBRA, this approximate eigenvalue is further refined using a variational principle to obtain fourth-order convergence with the mesh size. Richardson's extrapolation is then applied to a sequence of eigenvalues to estimate the exact eigenvalue using the coarsest possible mesh, thus minimizing the computational time.