The ISLAND module is used to compute magnetic island widths driven by saturated neoclassical tearingmodes in tokamak plasmas using a quasi-linear model published in Phys. Plasmas 11 (2003) 3460-3471. ! 1 Quasi-linear Tearing Mode Equations In this section, the equations and solution algorithm are derived for computing the widths of saturatedtearing mode magnetic islands using the quasi-linear theory approach. The derivation given in Ref. [3, 2] is extended here to include finite plasma pressure and the effect of the neoclassical bootstrap current. Inaddition, a self-consistent method for implementing this algorithm within an integrated modeling code is developed.

Last modified: Mon Dec 8 13:17:14 EST 2008