Laser Measurement of Anomalous Electron Diffusion in a Crossed-Field Plasma

Non-classical electron diffusion in crossed-field, low-temperature plasmas is measured experimentally. Laser-induced fluorescence and Thomson scattering are used to determine the inverse Hall parameter, a metric for cross-field transport, in a Hall ion source. The measured diffusion is found to depart from fluid model results at the peak electric field, remaining constant instead of exhibiting a sharp transport barrier. The implications of this result are discussed in terms of the current understanding of non-classical diffusion in low-temperature plasmas.