Search for ion temperature gradient driven electrostatic hydrodynamic instability in tokamaks

The ion temperature gradient driven electrostatic instability in tokamak magnetic geometry has been investigated numerically in terms of a generalized ion density moment. For typical tokamak parameters (ratio between the density gradient scale length and the major radius, εn = Ln/R, about 0 (0.1) and Ti approx.= Te) the search for rapidly growing instabilities of a hydrodynamic nature has been unsuccessful, even with the ion temperature gradient relative to the density gradient, ηi = d(ln Ti)/d(ln no), as large as six. (author). 19 refs, 4 figs