The measurement of the ratio of radial diffusion coefficient to mobility and the amplification coefficient for electrons at high E/p

A generalized method is given for the measurement of the amplification coefficient g and the ratio of radial diffusion coefficient to experimental mobility, D er /μ exp , for electron swarms moving through uniform electric fields in the presence of secondary electrons. The technique requires the experimental measurement of both the current amplification and the radial distribution of anode current. Measurements are reported for swarms in hydrogen for 30<or= E/p 0 <or=350 V cm −1 Torr −1 (at 0°C).