Effect of thermal fluctuations on the parametric instability in an inhomogeneous plasma

The effect of thermal fluctuations on the stationary level of noises amplified by the convective parametrical instability is considered. A term giving a thermal fluctuation level is included into a set of equations for the amplitude of interacting waves in inhomogeneous plasma. It is shown that if the damping of a wave parametrically amplified is rather strong (damping length is comparable with sizes of a resonant region), accountancy of this term results in considerable corrections for the amplitude amplification factors