The Value of Flexibility: the Contribution of RFX to the International Tokamak and Stellarator Programme

This paper highlights the contribution of RFX-mod Reversed Field Pinch to the wider fusion science program. This is done by illustrating some of the issues that tackled in the Reversed Field Pinch configuration find strong commonalities in Tokamak and/or Stellarators, and describing the direct cross configuration studies carried out on RFX-mod. The RFP has an intrinsic helical nature in the core which makes it an excellent test bed for the validation of Stellarator tools for equilibrium reconstruction. RFX can also be run as a circular low current Tokamak, which has been experimented down to sub q=2 equilibria in a stable way. Non circular shapes are being sought as well. RFX has unique capability of studying 3D physics, including details of turbulent structures at the edge, whereby ideas for possible control of the universal edge filamentary structures have been envisaged. Expanding the parameters space and tackling basic physics issues is the way the flexible RFX-mod device is contributing to secure the track towards ITER and DEMO.