The Value of Flexibility: the Contribution of RFX to the International TOKAMAK and STELLARATOR Programme

This paper highlights the contribution of RFX-mod R eversed Field Pinch to the wider fusion science pro gram. This is done by illustrating some of the issues tha t tackled in the Reversed Field Pinch configuration find strong commonalities in Tokamak and/or Stellarators, and d escribing the direct cross configuration studies ca rried out on RFX-mod. The RFP has an intrinsic helical nature in the core which makes it an excellent test bed f or the validation of Stellarator tools for equilibrium rec onstruction. 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 a re 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 structur es have been envisaged. Expanding the parameters space and tackl ing basic physics issues is the way the flexible RF X-mod device is contributing to secure the track towards ITER and DEMO.