Radial normal mode calculation of warm plasma stabilization of the drift cone mode

The fraction Δ of warm plasma needed to stabilize the drift cone mode is calculated for a loss cone plasma slab in a uniform magnetic field with R/sub p/approx.a/sub H/approx.k-1, where R/sub p/ is the width of the slab (representing the radial scale length), a/sub H/ is the hot ion Larmor radius, and k is the wavenumber of the mode. For 2XIIB-like parameters, a minimum Δ of 14% is needed for stability, which is consistent with experimental observations. This result is an improvement on previous calculations, which used the local approximation (assuming R/sub p/>>a/sub H/>>k-1) and gave a minimum Δ of 10% for the same parameters. Information is also obtained on the radial location and width of the normal modes, and on the effect of varying the warm plasma radial density profile