Development of plasma diagnostics as trigger for new physics: non-linear saturation mechanisms of plasma turbulence and dynamics of neutrals in fusion plasmas

Physics is an experimental science where theories should be confronted with experimental results. This validation process requires the development of plasma diagnostics to show that a new model faithfully represent physics reality, including quantitative assessments of discrepancies between theoretical and experimental results. From this perspective the direct experimental characterization of zonal flows, quantifying their role critical role in the non-linear saturation of plasma turbulence, and the interplay between neutrals and turbulent structures, an almost unexplored area of research, are great challenges for experimentalists.