EXPERIMENTAL INVESTIGATION OF TRANSPORT PHENOMENA IN THE SCRAPE-OFF LAYER AND DIVERTOR

Transport physics in the divertor and scrape-off layer of Alcator C-Mo d is investigated for a wide range of plasma conditions. parallel (par allel to) transport topics include: low recycling, high-recycling, and detached regimes, thermoelectric currents, asymmetric heat fluxes dri ven by thermoelectric currents, and reversed divertor flows. Perpendic ular (perpendicular to) transport topics include: expected and measure d scalings of perpendicular to gradients with local conditions, estima ted chi(perpendicular to) profiles and scalings, divertor neutral rete ntion effects, and L-mode/H-mode effects. Key results are: (i) classic al parallel to transport is obeyed with ion-neutral momentum coupling effects, (ii) perpendicular to heat transport is proportional to local gradients, (iii) chi(perpendicular to) proportional to T-e(-0.6) n(-0 .6) L-0.7 in L-mode, insensitive to toroidal field, (iv) chi(perpendic ular to) is dependent on divertor neutral retention, (v) H-mode transp ort barrier effects partially extend inside the SOL, (vi) inside/outsi de divertor asymmetries may be caused by a thermoelectric instability, and (vii) reversed parallel to flows depend on divertor asymmetries a nd their implicit ionization source imbalances.