Methods for field error analysis in the magnetic configuration of RFX

The magnetic field configuration of RFX is extensively investigated in order to understand the non-axisymmetric behaviour of the plasma, which clearly affects the plasma energy confinement properties in all the experimental discharges. Presently this analysis is focused on the local field errors, which are most likely related to the confinement anomaly. The effort is aimed at the reconstruction of the magnetic field in the plasma volume, by means of a number of algorithms, in order to distinguish between the plasma and the external conductor contributions and to analyse the harmonic properties of the magnetic perturbations. A description of the analysis methods and the main results obtained is reported.