The propagation of a cloud of hot electrons and generation of Langmuir waves are
investigated using numerical simulation of the quasilinear equations and analytical gas-
dynamic theory. The validity of the gas-dynamic theory is investigated and the accuracy of
Ryutov and Sagdeev's gas-dynamic equations is explored. It is found that inclusion of
spontaneous emission terms in the gas-dynamic equations is necessary for self-consistency
of analytical solutions. Results of numerical simulations show that the electron distribution …