Turbulent particle and energy fluxes to the first wall in DIII-D L-mode plasmas*

We report the heat flux deposited to the first wall, and its decay length λq, in the scrape-off layer (SOL) of lower single null L-mode discharges, obtained from a calculation of power balance. We determine 10-20% of the the power entering the SOL is deposited outside the main LSN divertor, to the first wall. The heat flux inferred from the power balance calculation, using bolometric and high-resolution divertor heat flux measurements, is benchmarked against the turbulent heat flux ob- tained from a scanning probe at the outer midplane. The probe measures electron density, electron temperature, electric field and their fluctuations, yielding radial profiles for the turbulent heat flux, consisting of convective and conductive contributions. This work contributes to the extrapolation of the first wall flux to be expected in phase 1 of Fusion Power Operation in ITER, as well as FPP.