Title | Filamentation in the RTP tokamak plasma |
Publication Type | Journal Article |
Year of Publication | 2001 |
Authors | M.NA Beurskens, N.JL Cardozo, E.R Arends, C.J Barth, H.J van der Meiden |
Journal | Plasma Physics and Controlled Fusion |
Volume | 43 |
Number | 1 |
Pagination | 13-38 |
Date Published | Jan |
ISBN Number | 0741-3335 |
Abstract | Experimental data are presented showing filamentation of the Rijnhuizen tokamak project (RTP) plasma. These filaments are only resolved by the high-resolution double pulse Thomson scattering diagnostic, and appear as multiple peaks in the T-e profile with a typical width of 5-10 mm and an amplitude as high as 1 keV in a 2 keV ambient plasma. This paper shows the occurrence of filaments under various plasma conditions. It shows that filaments are statistically significant plasma physical phenomena. A parameter study shows a weak dependence of their amplitude on q(a), whereas a strong inverse dependence on plasma density has been found. It takes filaments several milliseconds to develop after the switch-on of electron cyclotron heating; they are wiped out by a sawtooth crash and take only a few hundred microseconds to reappear after such a crash. They mainly occur in the centre of additionally heated plasmas by means of electron cyclotron heating, but have also been observed in transiently heated plasmas and off-axis in non-centrally heated plasmas. Finally, two interpretations of filament topology are tested by means of three experiments. It turns out that the interpretation of filaments as independent closed tube-like structures seems to best fit the RTP data. |
DOI | 10.1088/0741-3335/43/1/302 |
PID | fa1809833f9bbb41bb1f103aeccbf531 |
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