Coulomb contribution to the direct current electrical conductivity of dense partially ionized plasmas

The Coulomb contribution to the electrical conductivity of partially ionized plasmas is discussed and its general behavior is investigated. Recent experiments on the direct current conductivity in shock wave induced argon and xenon plasmas are analyzed in this context. Within the relaxation time approach, the Coulomb contribution is extracted by eliminating the contribution of scattering from neutrals. Alternatively, the Coulomb contribution can be calculated directly within linear-response theory. In particular, from the latter approach a generalized Spitzer factor is derived for taking into account electron-electron interactions within the relaxation time approximation. Experimental results for the Coulomb contribution to the electrical conductivity are in reasonable agreement with an interpolation formula derived from linear-response theory. (c) 2007 American Institute of Physics.