Electromagnetic oscillating two-stream instability of plasma waves

Near the resonance (ω/sub o/roughly-equalω/sub p/) a high-amplitude plasma wave decays into a purely growing electromagnetic perturbation and two Langmuir wave sidebands. The growth rate of the instability γapprox. =ω/sub p/k20v20/ 8k2v2/sub e/ for a Langmuir pump wave of finite wavenumber k0>kv/sub e//c and the threshold due to the finite extent, x0, of the pump is v20/v2/sub e/> or approx. =4k2v2/sub e/(k2x0+β)/ ω2/sub p/βx0; v0 and v/sub e/ are the oscillatory and thermal velocities of electrons and β is the x component of propagation vector k of the perturbation. This instability may be a possible source of spontaneous generation of random magnetic field in laser-produced plasmas