The momentum transfer cross section for low energy electrons in neon

Drift velocities have been measured at 77K and 293K for electrons in neon in the range 1.6*10 -3 <E+or-N(Td)<2 (1 townsend (Td)=10 -17 V cm 2 ). It was found that the drift velocities were very sensitive to the presence of traces of molecular gases, especially N 2 . Results of high accuracy required very high purity neon and, in particular, a knowledge of the N 2 impurity levels to better than 1 ppm. These data were used to determine the momentum transfer cross section for electrons in neon in the energy range 0.04<or= epsilon (eV)<or=6.0 Error limits of +or-1% are claimed for the drift velocity and +or-3% for the cross section.