Electrostatic fields and double layers at high power particle beam interaction with dense plasmas

A basically new result was derived numerically which may change the scenario of the study of plasma properties for inertial confinement fusion or similar interaction conditions. A genuine two fluid plasma code without any approximation or simplification with time steps much less than the plasma oscillation period (on 7600 and Cray) permits for the first time the study of the behaviour of inhomogeneous, irradiated, freely expanding, dense plasmas and overcomes the well known difficulties in the coupling by the Poisson equation. Remarkable damping mechanisms by coupling to ion oscillations have been observed. During this dynamical process with inhomogeneities in densities and temperatures of the two fluids, large electrostatic fields and double layers are generated sustaining for much longer times than the usually known decay of fields in conducting plasmas if densities and temperatures are spatially constant (homogeneous). The strong reduction of the thermal conduction within the areas of high fields suppresses the energy transport in fusion pellets. Advantages for ion beam fusion consist in the suppression of electron precursor waves from the hot corona to the pellet interior. This favours an interpenetration heating for the self-sustained fusion combustion fronts. Further conclusions are that tokamaks are rotating due to E × B - forces, which is a basic and general property of these systems.