Electron kinetics of ionization waves in helium positive columns

Electron kinetics related to ionization waves is discussed using the result s of temporally and radial-spatially resolved Langmuir probe measurements d uring propagation of an artificially excited ionization wave packet along a helium positive column at 0.55 Torr pressure and 200 mA discharge current. The results show a strong interdependence between the axial and radial ele ctric field fluctuations and the electron energy distribution fluctuations. Fluctuations in the electron energy distribution function related to the i onization waves revealed a complex energy spectrum whose low (0-10 eV) and high (10-25 eV) energy regions oscillate with opposite phases.