Transport Analysis in Low-collisionality w7-AS plasmas
نویسنده
چکیده
At W7-AS, the confinement properties are analyzed and compared mainly with neoclassical predictions for quite different conditions. Low density ECRH discharges allow access to the very long mean free path regime for electrons ( Q up to 4 keV at fl"= | 2Kt01e m-3) whereas combined NBL/ ECRH discharges at high density (7.= T/ 1 keV at fl.= I02o m-3) lead to high performance. Depending on the achieved temperatures, the experimental transport analysis in the plasma core is consistent with the neoclassical predictions. The experimentally observed "electron root" feature with strong E,) 0 is driven by the ECRH at high power levels. The neoclassical prediction of a purely thermal "electron root" is not supported experimentally. The standard neoclassical ordering scheme is violated for ions in case ofvery strong E .
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