The stochastic trigger of the neoclassical tearing mode (NTM) in toroidal confinement plasmas by the background turbulence is studied. The life time is given by the inverse of the statistical average of transition rate. On the basis of the statistical theory of a plasma turbulence, the life time of the state free from the NTM is obtained. The dependence on the plasma parameters is explicitly shown. The beta limit by the NTM is found to be diffused. This gives a new insight for the database of operational boundary of toroidal plasmas.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)