The stability of the flute modes in the bumpy torus is studied when plasma β(ion beta) is finite.
In this study, we use a model with the bumpiless cylinder and rigid ring.
Analysis contains the ambipolar electric field and the finite Larmor radius effects.
The results show that in comparision with the zero plasma β case the finite plasma β has the effect of increasing the flute instability.
Given the plasma β, the ring β has the threshold value beyond which the flute mode is stabilized.
This threshold value for stability increases linearly with the plasma β.