Radial fluctuation scale of ion temperature gradient driven turbulence

We show that ion temperature gradient driven turbulence supports fluctuations with broader radial scales than those inferred previously on the basis of the eigenfunction with lowest radial eigenmode number. These fluctuations of greater radial extent are more strongly excited and are shown to result in fluctuation levels and transport coefficients which can be considerably larger than those previously predicted. It is expected that transport of this nature would force ion temperature and density profiles to near-marginal stability in neutral beam and ICRF heated plasmas. 14 refs., 6 figs