Physics of Collapses - Probabilistic Occurrence of ELMs and Crashes -

A statistical picture for the collapse is proposed. The physics picture of the crash phenomenon, which is based on the turbulence-turbulence transition, is extended to include the statistical variance of observables. The dynamics of the plasma gradient and the turbulence level are examined, with the hysteresis nature in the flux-gradient relation. Probabilistic excitation is predicted. The critical condition is described by the statistical probability.