Transport coefficients for lithium ions in nitrogen

Abstract

The mobility mu and the longitudinal and transverse diffusion coefficients DL and DT have been measured for 7Li+ ions in N2 gas, at 295 K and field to density values E/n0 up to 600 Td. At low values of E/n0, clustering reactions distorted the measured current density distributions and arrival time spectra. The diffusion coefficients could therefore be determined accurately only for E/n040 Td, while the mobility was determined down to 12 Td. The experimental values of DL/ mu and DT/ mu were compared with values calculated from the experimental mobility values, using generalised Nernst-Townsend relations and neglecting inelastic collisions. Large discrepancies were found over the whole E/n0 range, showing the crucial importance of inelastic energy losses for the swarm behaviour.