Nonextensivity in nonequilibrium plasma systems with Coulombian long-range interactions

The nonextensivity in a nonisothermal plasma system with the Coulombian long-range interaction is studied in the framework of Tsallis statistics. We present for first time a mathematical expression of the nonextensive parameter q based on the mathematical theory about the generalized Boltzmann equation and the q-H theorem and the Maxwellian q-velocity distribution. We obtain a new physical explanation for q not equal 1 related to the nature of nonisothermal configurations in the plasma systems with the Coulombian long-range interaction, which means that Tsallis statistics might be a suitable statistics for the description of a nonequilibrium system with long-range interactions and with a temperature gradient in it. (C) 2004 Elsevier B.V. All rights reserved.