Electron beam generated plasmas have a variety of unique features that make them distinctive plasma sources for materials processing. They are characterized by high plasma density, very low electron temperature, and unique gas phase chemistries that distinguish them discharge based plasmas. This work presents frequency probe and Langmuir probe measurements (where applicable) of plasma density over a range of 10⁹ to 10¹² cm^-3 in a variety of processing plasma chemistries. This work also features the effect of varying gas chemistry on energy distribution function measurements as well as OES (optical emission spectroscopy) and mass spectrometry measurements.