AbstractThe amplification of low frequency electrostatic waves as the result of beam plasma interaction is considered. In order to find the dependence of the growtherate from frequency and the plasma parameters the dispersion equation has been solved numerically for some given values of ion and electron temperatures and the drift velocity of the electrons. The results show positive growthrates (amplification) in the whole frequency range<ω ≲ ωiis the corresponding ion plasma frequency.The growthrates are large for low temperatures and decrease with rising temperatures and decreasing drift velocity. The phase velocity increases with rising temperatu