Collisional damping of surface ion-acoustic mode in the semi-bounded and collisional plasmas

The dissipation of ion-acoustic surface waves in a semi-bounded and collisional plasma is evaluated from the dispersion integral formulated by employing the specular reflection boundary condition. The distinction between the collisionless Landau damping and collisional damping is addressed here. The collisional damping of the surface wave is investigated for two ionization cases: weakly ionized and completely ionized plasmas. In the case of weakly ionized plasma, the damping is found to be independent of the ion temperature, but it has been shown that the ion temperature can play an important role in the fully ionized plasma. Particularly, in the case of weakly ionized plasma, the effect of collisional damping hardly appears in the small wave number region. However, the collisional damping is important for the fully ionized plasma in the small wave number region. For both weakly ionized and fully ionized plasmas, the collisional damping dominates over the collisionless Landau damping in the large wave number region.