Electron detachment cross sections of CH4 - colliding with O2 and N2 below 10 keV energies

Negative methane is an interesting molecular anion from a fundamental point of view and also because it can be a source of thermal electrons in low temperature hydrocarbon plasma. Measurements of collisional electron detachment from methane anions colliding with O2 and N2 in the energy range of 0.3 to 10.0 keV are presented. Single electron detachment was measured with the signal grow-rate method and total electron detachment was measured with the beam attenuation technique. Both techniques were employed in order to study the process of electron detachment over the present energy range. The validity of the geometrical model is discussed. © 2014 IOP Publishing Ltd