Author/Authors :
Gunn، نويسنده , , J.P and Boucher، نويسنده , , C. and Dionne، نويسنده , , M. and ?uran، نويسنده , , I. and Fuchs، نويسنده , , V. and Loarer، نويسنده , , T. and Nanobashvili، نويسنده , , I. and P?nek، نويسنده , , R. and Pascal، نويسنده , , M.-G. Saint-Laurent، نويسنده , , F. and St?ckel، نويسنده , , J. and Van Rompuy، نويسنده , , T. and Zag?rski، نويسنده , , R. and Ad?mek، نويسنده , , J. and Bucalossi، نويسنده , , J. and Dejarnac، نويسنده , , R. and Devynck، نويسنده , , P. and Hertout، نويسنده , , P. and Hron، نويسنده , , M. and Lebrun، نويسنده , , G. and Moreau، نويسنده , , P. and Rimini، نويسنده , , F. and Sarkissian، نويسنده , , A. and Van Oost، نويسنده , , G.، نويسنده ,
Abstract :
Near-sonic parallel flows are systematically observed in the far scrape-off layer (SOL) of the limiter tokamak Tore Supra, as in many L-mode X-point divertor tokamak plasmas. The poloidal variation of the parallel flow has been measured by moving the contact point of a small circular plasma onto limiters at different poloidal angles. The resulting variations of flow are consistent with the existence of a poloidally localized enhancement of radial transport concentrated in a 30° sector near the outboard midplane. If the plasma contact point is placed on the inboard limiters, then the SOL expands to fill all the space between the plasma and the outboard limiters, with density decay lengths between 10 and 20 cm. On the other hand, if the contact point lies on the outboard limiters, the localized plasma outflux is scraped off and the SOL is very thin with decay lengths around 2–3 cm. The outboard radial transport would have to be about two orders of magnitude stronger than inboard to explain these results.
