The ratio of radial diffusion coefficient to mobility for electrons in helium, argon, air, methane and nitric oxide

Abstract

The ratio of the radial diffusion coefficient to mobility Dr/ mu exp has been measured for the first time in five gases at high E/N (ratio of electric field to gas number density). The range of E/N was as follows: helium 3<or=E/N<or=847 Td; argon 8<or=E/N<or=1271 Td; air 14<or=E/N<or=1412 Td; methane 14<or=E/N<or=5650 Td; nitric oxide 56<or=E/N<or=1412 Td. The Townsend ionization coefficient alpha T/N has also been measured in each gas for the same E/N range.