Abstract. Magnetic reconnection in weakly collisional plasma regimes, that are relevant burning plasma tokamak experiments, is discussed. In particular: 1) It is shown that the sawtooth crash time is determined by electron compressibility and the electron inertia skin depth; 2) Irreversibility in collisionless reconnection is introduced by a spatial phase mixing process of conserved fields; 3) Driven reconnection in the vicinity of a magnetic separatrix is discussed, and an interpretation of the VTF magnetic reconnection experiment at MIT is offered; 4) Drift-tearing modes in weakly collisional regimes are shown to be stabilised by coupling with drift-acoustic waves, which strikes a note of optimism as far as the stability of ITER-FEAT against neoclassical tearing modes is concerned; 5) A further stabilising effect for these modes is shown to be associated with sheared plasma flows; 6) Peculiar sawtooth traces in the FTU experiment may also be interpreted in terms of non-rigid plasma rotation in the plasma cemtral region within the mixing radius.
IAEA 2003