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, n = L n /R, about 0 (0.1) and T i ≅T e ) the search for rapidly growing instabilities of a hydrodynamic nature has been unsuccessful, even with the ion temperature gradient relative to the density gradient, η i = d(ln T i )/d(ln n 0 ), as large as six.