engUniversité de LorraineOpen Plasma Science3076-14682025-02-24Volume 110.46298/ops.1464114641journal articleE. Fable0https://orcid.org/0000-0001-5019-9685G. Tardini0https://orcid.org/0009-0002-0544-6880L. Giannone0https://orcid.org/0000-0001-5611-200Xthe ASDEX Upgrade TeamMax-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, 85748 Garching, GermanyA new axisymmetric equilibrium solver has been written, called FEQIS (Flexible EQuIlibrium Solver), which purpose is to be used inside integrated modeling of tokamak plasmas. The FEQIS code solves the Grad-Shafranov equation and the "circuit" equations for the external coils and passive conducting structures that are toroidally connected. The code has been specifically equipped with flexibility in choice of circuit connections, and a stripped-down numerical scheme for the solution of the Grad-Shafranov equation through a structure of multi-level simplifications which can be tested against the required accuracy.http://ops.episciences.org/14641/pdfPlasma Physics