Relaxation of suprathermal electrons due to coulomb collisions in a plasma

The relaxation of a slightly suprathermal test electron beam in a quiescent, turbulence free target plasma is measured and compared with the dynamical diffusion predicted by the Fokker-Planck equation. Within an experimental error there is agreement between measurement and calculation. The results are compared to relaxation phenomena (dynamical convection) occurring, when turbulence is introduced into the target plasma either by the test electron beam or by the plasma source. (author)