MHD analysis before BCs has been carried out by SVD. Such analysis showed that modes with high n up to 5 are present before the BC and in certain cases they act as precursor (Fig.2 and 4) showing a fast growth in -10ms. This is in contrast with previous CW observations of a BC triggering by a n=1 kink like mode [1,3]. RFA enhancement (Fig.3) for βN>2.5 shows that plasma pressure is approaching the no-wall beta limit. This is found in good agreement with the concentration of BC in the qmin-βN diagram (Fig.4).
|Titolo:||MHD analysis of Beta Collapses in AT JET discharges|
|Data di pubblicazione:||2015|
|Appare nelle tipologie:||4.1 Contributo in Atti di convegno|