Abstract
A general method is developed for the calculation of the conductivity tensor, collisional contribution included, associated with a wave in a plasma in a magnetic field. The method is based on an iterative procedure and is applicable to any kinetic equation. With the Landau collision term a result valid to all orders in k2λD2 is given in integral form, and the electron current contribution is calculated explicitly to order k2λD2. The leading contributions resulting from the ion motion are also obtained.