a1 Institute of Theoretical Astrophysics, University of Oslo, Boks 1029 Blindern, N-0315 Oslo, Norway
a2 Institute of Physics, University of Oslo, Boks 1048 Blindern, N-0316 Oslo, Norway
a3 Department of Plasma Physics, Umeå University, S-901 87 Umeå, Sweden
a4 Institute of Theoretical Astrophysics, University of Oslo, Boks 1029 Blindern, N-0315 Oslo, Norway
Dynamical equations are derived for the evolution of weakly nonlinear electron plasma waves when the electron distributions are characterized by more than one temperature component. The presence of electron-acoustic modes in multi- temperature plasmas opens a new decay channel. By considering an explicit example, it is demonstrated that these distributions imply significant modifications of the standard models for the decay spectrum of electron plasma waves. In particular, long-wavelength Langmuir waves can decay to shorter wavelengths. The results can have implications for ionospheric heating experiments.
(Received January 10 1994)
(Revised April 07 1994)