THEORETICAL STUDY AND NUMERICAL SIMULATION OF

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					                XXXII conference on plasma physics and CF, February 14 – 18, 2005, Zvenigorod



   THEORETICAL STUDY AND NUMERICAL SIMULATION OF NONEQUILIBRIUM
  ELECTRON DISTRIBUTION FUNCTIONS IN SOLID-STATE PLASMAS AND THEIR
                           APPLICATIONS

                                       V.I. Karas , I.F. Potapenko*

                  NSC “Kharkov Institute of Physics & Technology, Kharkov, Ukraine
                  *
                    Keldysh Institute of Applied Mathematics of the RAS, Moscow, Russia

   In present report the formation of a non-equilibrium (NE) distribution is studied. Consideration is
based on the one dimensional non-linear kinetic equation of a Landau - Fokker - Planck (LFP) type
in the presence of particle (energy) sources and sinks (see [1-3]). The rigorous asymptotic
estimation and the applicability conditions for the asymptotic steady-state solution is given. NE
quasi steady-state local DF exist inside the momentum interval between the energy particle) source
and the bulk (or sink) of the particle distribution and has the form of gradually decreasing functions.
From our consideration it follows that even the relative smallness of sources may imply a drastic
deviation of the steady-state DF from the equilibrium DF. The density of the current carriers
governs the conduction characteristics of the medium, so that, in semiconductor plasma with a
electron NEDF, this density is very high, in contrast to the case of the equilibrium DF with the
exponential distribution decreasing. That is why, under intense fluxes both of electromagnetic
radiation and fast particles, the emission and conduction properties of semiconductor plasma can
become anoma-lous. Numerical simulation is in good agreement with the analytical results and with
the results obtained in experiments on irradiation of a thin GaAs film by a fast ion beam. The
electron energetic spectrum differs from one that formed under the stationary source action. The
comparison of the simulation and experimental results shows that the taking into account of the
non-stationary source character may be the determining factor. Obtained results can be useful in
connection with the development of high-power particle and energy sources and for the prediction
of the semiconductor behaviour under the action of particle fluxes or electromagnetic radiation.
   We are grateful to STCU (project # 1862) for partial financial support of this work.

References
[1]. Kononenko S.I., Balebanov V.M., Zhurenko V.P., Kalantar`yan O.V., Karas` V.I., Kolesnik
     V.T., Muratov V.I., Novikov V.E., Potapenko I.F., Sagdeev R.Z. Plas. Phys. Rep. 2004, v.30,
     p.687.
[2]. I.F. Potapenko, A.V. Bobylev, C.A. de Azevedo, and A.S. de Assis. Phys. Rev. E. 1997, v.56,
     p.7159.
[3]. V.I. Karas`, I.F. Potapenko. Plasma Phys. Rep. 2002, v.28, p.837.