Debye shielding in a nonextensive plasma

The phenomenon of Debye Shielding is revisited within the theoretical framework of the Tsallis statistical mechanics. The plasma consists of nonextensive electrons and ions. Both the effective Debye length lambda(q)(D) and the fall-off of the electrostatic potential Phi are considered and a parameter study conducted. Owing to electron nonextensivity, the critical Mach number derived from the modified Bohm sheath criterion may become less than unity allowing therefore ions with speed less than ion-acoustic speed to enter the sheath from the main body of the plasma. Considering the wide relevance of collective processes, our analysis may be viewed as a first step toward a more comprehensive Debye shielding and electrostatic plasma sheath in nonequilibrium plasmas. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3577599]