The SEL macroscopic modeling code Original Research Article

The SEL (Spectral ELement) macroscopic modeling code for magnetically confined plasma combines adaptive spectral element spatial discretization and nonlinearly implicit time stepping via Newtonʹs method on massively parallel computers. Static condensation is implemented to construct the Shur complement of the Jacobian matrix, which greatly accelerates the linear system solution and distinguishes itself from conventional Newton–Krylov schemes. Grid alignment with the evolving magnetic field, implemented with a variational principle, is a key component of grid adaptation in SEL, and is critical to toroidal plasma applications. Results of 2D magnetic reconnection are shown to illustrate the accuracy and efficiency of the parallel algorithms built on the Portable, Extensible Toolkits for Scientific Computing (PETSC) framework.