A theory for the superbanana plateau resonance that occurs at the phase space boundary is presented to refine the comprehensive theory for neoclassical toroidal plasma viscosity in tokamaks. The results of the theory reproduce those of the standard superbanana plateau resonance theory when the resonance occurs away from the boundary. It shows that the strength of the superbanana plateau resonance weakens in the vicinity of the phase space boundary. It also indicates that it is important to know the resonance pitch angle parameter when comparing the results of the superbanana plateau resonance with those of the experiments. The theory is used to refine the kernel for the superbanana plateau resonance in the approximate expression for the neoclassical toroidal plasma viscosity.
Collisional dependence of Alfvén mode saturation in tokamaks