Electron drift velocity in hydrogen, nitrogen, oxygen, carbon monoxide, carbon dioxide and air at moderate E/N

The drift velocity of electrons in hydrogen, nitrogen, oxygen, carbon monoxide, carbon dioxide, and air free from water vapour and carbon dioxide, at ambient temperatures (293-296K) has been measured by the modified Bradbury-Nielsen time-of-flight method over the range of the reduced electric field E/N: 0.05<or=E/N<or=250 Td, 0.1<or=E/N<or=250 Td, 1.0<or=E/N<or=275 Td, 0.1<or=E/N<or=150 Td, 0.6<or=E/N<or=250 Td and 0.05<or=E/N<or=400 Td respectively. The present results are compared with those obtained by other investigators.