Abstract
Precise electron density (ne approximately=1018 cm-3) and temperature (T approximately=1 eV) profiles have been obtained in high-pressure (p approximately=10 bar) pulsed arcs produced in noble-gas filled flashlamps. These quasi-stationary (1 ms) dense plasmas show a flat profile over 2/3 of their diameter and are highly ionised ( alpha >60%). Such experimental situations allow reliable measurements of the electrical (DC) conductivity and comparison with theoretical works. The experimental values are significantly lower than Spitzer's (1962). Recalling the main features of the line profiles, which lead to the conclusion that the plasma becomes less collisional, the authors propose that scattering by oscillating microfields originating in plasma waves may explain the high electron-ion collision frequency (v)ei.