THEORY OF WEAK DUST ACOUSTIC DOUBLE-LAYERS

We present a theoretical model to investigate the existence of small a mplitude dust acoustic double layers in a plasma consisting of highly charged mobile dust grains in the background of hot electrons and ions . We show that in the presence of isothermal hot electrons a double la yers solution can exist only when dust particles are positively charge d. On the other hand, in case of nonisothermal hot electrons double la yers can exist only when dust particles are negatively charged. In bot h cases only a compressive type of double layers solution is found to occur.