THE POLARIZATION TENSOR OF A NONRELATIVISTIC PLASMA

Field equations for the coupled system of Schrodinger and Maxwell fiel ds are derived from a Lagrange density including external sources. To use Coulomb gauge, the concept of transverse fields is taken. Green fu nctions are defined via functional derivatives. Vertex functions are i ntroduced for the longitudinal Coulomb interaction and for the transve rse interaction. The polarization tensor is discussed in the one-loop or RPA-approximation. The static limit is derived for the longitudinal and the transverse components of the polarization tensor. For the lon gitudinal part we get the square of the inverse Debye radius, as usual . The transverse part vanishes in first order approximation. The diele ctric tensor is introduced, the long wavelength limit is discussed. Th e classical limit of our results is identical with the results of Klim ontovich.