Boundary Fluctuations and Transport During Detachment

Divertor plasma turbulence levels increase when detachment is approached in DIII-D. The root mean square of fluctuation levels of saturation current, floating potential, electron temperature and density measured by a divertor scanning probe increase > 100% of average levels as the divertor plasma starts detaching(Te<10eV)Data from divertor Thomson Scattering and target probes show a scatter of 100% of the mean value, consistent with probe measurements. Increased plasma fluctuation levels often lead to enhanced radial particle and heat transport and to divertor plasma mixing. Fluctuation levels at the midplane feature increased turbulent transport by ~50% during detachment. Modelling by SOLPS5.1 with enhanced transport coefficients are performed and compared to experiments.