Explosive behavior of some pressure-driven modes

The quadrupole geometry of the m/n = 2/1 component of an n = 1 kink-ballooning mode is shown to result in an explosive ballooning finger that leads to a very fast, almost precursor-free disruption. The ballooning finger convects the hot plasma from the core to the edge on Alfven time scales, in agreement with some experimental observations. The fast time scale of the ensuing disruption would make any mitigation attempt difficult if not impossible; thus, this type of disruption has to be avoided, which can only be achieved with a thorough understanding of the underlying physics. (author)