Evidence on the effects of main-chamber neutrals on density shoulder broadening

Evidence that density shoulder broadening is dependent on high main-chamber neutral density is presented. Shoulder broadening does notoccur when the sources for main-chamber neutrals are minimized using divertor baffles and wide gaps to the first wall (similar to 3x the densitydecay length). Removing the baffles or reducing the gap to the inner wall both act to increase the density shoulder amplitude in otherwiseidentical TCV discharges. Radial turbulent transport is correlated with shoulder amplitude. (C) Published under an exclusive license by AIP Publishing