MHD activity in FTU plasmas with reversed magnetic shear
P Buratti; F Alladio; P Micozzi; O Tudisco; L Acitelli; B Angelini; M L Apicella; G Apruzzese; E Barbato; A Bertocchi; G Bracco; A Bruschi; G Buceti; A Cardinali; C Centioli; R Cesario; S Ciattaglia; M Ciotti; S Cirant; V Cocilovo; F Crisanti; R De Angelis; F De Marco; B Esposito; D Frigione; L Gabellieri; G Gatti; E Giovannozzi; C Gourlan; G Granucci; M Grolli; A Imparato; H Kroegler; M Leigheb; L Lovisetto; G Maddaluno; G Maffia; A Mancuso; M Marinucci; G Mazzitelli; F Mirizzi; F P Orsitto; D Pacella; L Panaccione; M Panella; V Pericoli Ridolfini; L Pieroni; S Podda; G B Righetti; F Romanelli; F Santini; M Sassi; S E Segre; A Simonetto; C Sozzi; S Sternini; A A Tuccillo; F Valente; V Vitale; G Vlad; V Zanza; M Zerbini
Журнал:
Plasma Physics and Controlled Fusion
Дата:
1997-12-01
Аннотация:
The MHD activity of plasma configurations with reversed magnetic shear has been investigated on the FTU tokamak. In the presence of pairs of surfaces with the same rational value q = m/n of the safety factor, double-tearing modes are excited which give rise in most cases to bursts of sawtooth-like profile rearrangements. More stable regimes have also been found, in which the activity is dominated by rotating saturated modes. In a particular case with and a discharge without any detectable MHD activity during the current flat-top has been obtained. In high-temperature regimes ( at ), an irregular activity has been detected near the plasma centre which could be due to the excitation of resistive interchange modes.
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