Low-frequency drift wave in a tokamak

The primary mechanism for the excitation of drift waves in a tokamak involves the collisions of trapped electrons and gives rise to waves with frequencies below the effective collision rate: ω>ν/sub e//epsilon. In a tokamak with fusion-level parameters this frequency is on the order or even less than the bounce frequency of the trapped ions ν/sub e//epsilon<ω/sub bi/, so that the frequency of the waves which are excited is ω<ω/sub bi/. A drift wave in this new frequency region is analyzed. Its poloidal and radial structures are studied. The effects of various dissipative factors are studied. An instability condition is derived: Vertical Bard ln q /d ln n0Vertical Bar