ON THE RELAXATION OF COLD ELECTRONS AND HOT IONS

The relaxation process of a space uniform plasma composed of cold elec trons and one species of hot ions is studied numerically using one-and two-dimensional Landau-Fokker-Planck codes. Relaxation of a monoenerg etic ion beam is considered in possibly extreme temperature regimes. S pecial attention is paid to the deviation of the relaxation process fr om the classical picture, which is characterized by the close initial temperatures T-e much greater than (m(e)/m(i))T-1/3(i). The present re sults give quite a clear idea of the relaxation picture for any initia l temperatures also in extreme temperature regimes. A difference schem e, preserving the number of particles and the energy, gives the possib ility of solving the problem numerically without error accumulation, e xcept for machine errors. (C) 1998 American Institute of Physics.