Secondary ionization by metastable particles in nitrogen

Publisher Website
Google Scholar
Abstract
The spatial dependence of the coefficient for secondary electron emission by N2(A 3 Sigma u +) metastable molecule impact on the cathode in an ionization growth experiment in nitrogen at E/p=100 V cm-1 Torr-1 is examined over a wide range of electron separations. The measurements provide the first detailed experimental confirmation of the fractional diffusion theory in which the spatial dependence is predicted. In particular, the effects of trace concentrations of impurity of the metastable particle population have been evaluated quantitatively, enabling the extrapolation of the data to the case of ionization growth in nitrogen which is free of impurity contamination. The effects of impurities on the cathode surface are examined and the efficiency of secondary electron production following metastable particle impact is estimated.