Stability of low frequency modes in a hot electron Bumpy Torus

The system of equations appropriate for describing low frequency modes (OMEGA < OMEGA/sub i/) in general geometry for a three-species plasma is derived. The derivation employs an eikonal ansatz and for simplicity assumes Maxwellian unperturbed distribution functions, but permits arbitrary beta and asymmetry. The full system of equations includes ballooning, interchange and compressional Alfven modes. As examples, two limits of the general results are employed to study EBT stability. The first example, a local analysis of the high phase velocity ring model, leads to analytic estimates of stability boundaries due to interchange and compressional Alfven modes, which agree with numerical solutions. In the second example, the hot electrons are treated as a trapped species and, in the limit of pure magnetic perturbations, the magnetic trapped particle mode is recovered