Formation of thermoelectric field in a collisionless non-equilibrium plasma

Summary form only given, as follows. A microscopic approach to calculating the macroscopic electric field in a weakly inhomogeneous, collisionless plasma is formulated, and the explanation of the mechanism of field formation is given. The thermoelectric field is shown to be caused by the difference in dynamical screening of electrons and ions in an inhomogeneous plasma. A universal analytic expression for the thermoelectric potential in a non-isothermal plasma is derived, which takes into account the quasineutrality and weak temperature inhomogeneity. The influence of this thermoelectric field upon local plasma macroscopic parameters and the competition of the electron and ion contributions to the thermoelectric coefficient are investigated. Numerical results for various spatial profiles of plasma temperature and density in tokamak plasmas appear to be in good agreement with the corresponding experimental data on electric potential profiles, including the change of potential´s sign at the plasma periphery.