Effect of plasma inhomogeneity and electron-ion collisions on growth characteristics of a plasma-filled Cherenkov laser

Growth characteristics of a Cherenkov laser filled with background plasma with a transversely inhomogeneous density profile are discussed with the aid of the multilayer approximation method. The accuracy of the numerical results is confirmed by comparison with the available analytical solution. The effect of electron-ion collisions in the background plasma is also considered. In particular, a noticeable degradation in growth characteristics is found. However, by a proper choice of various parameters, spatial growth rates are kept at the level well over those of the corresponding vacuum devices.