Large amplitude electrostatic solitary structures in a hot non-thermal dusty plasma

A rigorous theoretical investigation has been made of large amplitude compr essive and rarefactive dust-acoustic solitary waves in an unmagnetized hot dusty plasma consisting of a negatively charged hot dust fluid and non-ther mally distributed ions. The pseudo-potential approach, which is valid for a rbitrary amplitude solitary waves, has been employed. It is shown that the presence of the fast or non-thermal ions may allow compressive and rarefact ive solitary waves to coexist. It is found that the effect of the dust flui d temperature changes the minimum values of alpha (a parameter determining the number of fast ions present in our dusty plasma model) and M (the Mach number) for which the compressive and rarefactive solitary waves can coexis t. It is also observed that as the dust fluid temperature rises, the amplit ude of both the compressive and rarefactive solitary waves decrease, wherea s their width increases. The implications of these results to some space an d astrophysical dusty plasma situations are briefly discussed. (C) 2000 Els evier Science Ltd. All rights reserved.