Published online by Cambridge University Press: 13 March 2009
The stability of oblique modulation of ion-acoustic waves in a collisional plasma with one and two electron-temperature distributions is studied using the KBM method. For the case of one electron distribution it is found that collisions give rise to regions of physical instability that are otherwise stable in the absence of collisions. For the two-electron-distribution case in the presence of collisions the domains of physical instability of the wave are studied with respect to the values of the temperature ratio and relative concentration of the two electron species.