Ifwe want the fusion medium to be sustainable, we should at least provide Lawson criterion. Because of the existence of some instabilities in plasma, this medium should be heated. There are some methods for this purpose and the best way in very high temperatures is using the radio frequency wave heating (RF). Propagating the incident light wave through a plasma whose density is rippled along the direction of propagation by density fluctuations associated with the ion-acoustic wave (IAW), creates a small amplitude scattered electromagnetic (EM) wave, with all waves obeying Manley-Rowe relations (conservation laws for energy and momentum). Superposition of the incident pump EM wave and the scattered EM wave leads to the creation of Pondermotive force. Raising the intensity of the incident light wave causes the Pondermotive force to be strong enough that increases the density fluctuations of the original IAW mode which is called unstable (stimulated). This force increases the amplitude of the ion density fluctuations. Higher ion density fluctuations again provide a strong scattering of the incident EM wave. Due to this feedback loop, an instability is possible called Stimulated Brillouin Scattering () and is categorized as a parametric instability. The instability growth rate is the most important parameter that is investigated in this thesis. Dependence of this parameter on incident light wave frequency is verified. Increasing the incident light wave from 118 GHz to 128 GHz causes the instability growth rate to decrease. Furthermore, since in the high temperatures a kind of damping so-called Landau damping is dominant, this factor is investigated as well. By increasing the damping, the instability growth rate decreases. In this thesis the density profile is obtained by solving the Fourier transformed Vlasov equation in the velocity space.
