A technique for calculating finite Larmor radius corrections

Finite Larmor radius corrections may be significant in plasma stability theory, and the geometry of the cylindrical pinch is appropriate for theoretical development. The study presented here is limited to calculation of the perturbation of the energy of a particle by a normal mode disturbance. This is found to be complicated when terms proportional to the square of the Larmor radius are retained. It is concluded that stability theory becomes identical with drift wave theory in complex geometry.