TY - GEN
T1 - Evidence of bi-fluid destabilization of a double tearing mode in Tore Supra
AU - Maget, P.
AU - Meshcheriakov, D.
AU - Artaud, J. F.
AU - Lotte, Ph
AU - Ségui, J. L.
AU - Lütjens, H.
AU - Mellet, N.
PY - 2012/12/1
Y1 - 2012/12/1
N2 - Tearing modes associated to hollow current profiles are prone to grow in moderate performance plasmas, and often constrain the realisation of non inductive discharges in Tore Supra [1]. The prediction of MHD boundaries in such scenarios is complicated by the importance of diamagnetic effects, combined with curvature stabilization, which determine the stability of these modes and depends on details of the pressure and density profiles [2]. The weak MHD stability is illustrated here by the growth of a (5,3) Double-Tearing Mode (DTM) after the switch-off of 3MW of ICRH, and a moderate change of equilibrium profiles in the core, while 5MW of LH maintains the major part of plasma current and electron heat source. This observation has been analyzed with the two-fluid non linear MHD code XTOR-2F [3], on the basis of a CRONOS integrated simulation [4]. It appears that diamagnetic effects [2], as well as neoclassical friction [5], are playing a key role in the linear and non linear regimes in these conditions, and are required for explaining the observed pressure crash driven by the (5,3) DTM.
AB - Tearing modes associated to hollow current profiles are prone to grow in moderate performance plasmas, and often constrain the realisation of non inductive discharges in Tore Supra [1]. The prediction of MHD boundaries in such scenarios is complicated by the importance of diamagnetic effects, combined with curvature stabilization, which determine the stability of these modes and depends on details of the pressure and density profiles [2]. The weak MHD stability is illustrated here by the growth of a (5,3) Double-Tearing Mode (DTM) after the switch-off of 3MW of ICRH, and a moderate change of equilibrium profiles in the core, while 5MW of LH maintains the major part of plasma current and electron heat source. This observation has been analyzed with the two-fluid non linear MHD code XTOR-2F [3], on the basis of a CRONOS integrated simulation [4]. It appears that diamagnetic effects [2], as well as neoclassical friction [5], are playing a key role in the linear and non linear regimes in these conditions, and are required for explaining the observed pressure crash driven by the (5,3) DTM.
M3 - Conference contribution
AN - SCOPUS:84876933320
SN - 9781622769810
T3 - 39th EPS Conference on Plasma Physics 2012, EPS 2012 and the 16th International Congress on Plasma Physics
SP - 429
EP - 432
BT - 39th EPS Conference on Plasma Physics 2012, EPS 2012 and the 16th International Congress on Plasma Physics
T2 - 39th EPS Conference on Plasma Physics 2012, EPS 2012 and the 16th International Congress on Plasma Physics
Y2 - 2 July 2012 through 6 July 2012
ER -