  The evolution of a solar flare accelerated non-thermal electron population
and associated plasma emission is considered in collisional inhomogeneous
plasma. Non-thermal electrons collisionally evolve to become unstable and
generate Langmuir waves, which may lead to intense radio emission. We
self-consistently simulated the collisional relaxation of electrons,
wave-particle interactions, and non-linear Langmuir wave evolution in plasma
with density fluctuations. Additionally, we simulated the scattering, decay,
and coalescence of the Langmuir waves which produce radio emission at the
fundamental or the harmonic of the plasma frequency, using an angle-averaged
emission model. Long-wavelength density fluctuations, such as are observed in
the corona, are seen to strongly suppress the levels of radio emission, meaning
that a high level of Langmuir waves can be present without visible radio
emission. Additionally, in homogeneous plasma, the emission shows time and
frequency variations that could be smoothed out by density inhomogeneities.
