GENERATION OF DIPOLAR STRUCTURES IN DRIFT-WAVE TURBULENCE

The dynamics of modulational interaction between short wavelength drif t waves and long wavelength trapped ion convective cells are investiga ted,. It is shown that modulational instability growth rates can excee d linear trapped ion mode growth rates. A simple set of envelope equat ions for this system has been derived and solved. A quasi-universal fi nal state of dipolar anisotropic convective cells with trapped drift w aves is indicated. Drift waves with k(perpendicular-to)rho(s) greater- than-or-equal-to 1 are trapped and undergo strong modulation.