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 not occur when the sources for main-chamber neutrals are minimized using divertor baffles and wide gaps to the first wall (~3× the density decay length). Removing the baffles or reducing the gap to the inner wall both act to increase the density shoulder amplitude in otherwise identical TCV discharges. Radial turbulent transport is correlated with shoulder amplitude.. Authors: Tsui, C. K. [University of California, San Diego, CA (United States); Univ. of California, San Diego, CA (United States)] (ORCID:0000000273468312); Boedo, J. A. [University of California, San Diego, CA (United States)] (ORCID:0000000322304112); Brida, D. [Max Planck Institute for Plasma Physics, Garching (Germany)]; Février, O. [Ecole Polytechnique Federale Lausanne (EPFL) (Switzerland)] (ORCID:0000000292907413); Harrer, G. F. [Technical University of Vienna (Austria)] (ORCID:0000000211503987). DOE Contract: SC0010529. Subjects: 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; Langmuir turbulence; plasma material interactions; plasma properties and parameters; plasma turbulence; tokamaks