Scanning anode field emission microscopy for studies of planar cathodes

Total field emission current in function of applied voltage, known as (I-V) characteristics, from planar cathodes were currently measured with a scanning anode field emission microscope (SAFEM). As the field distribution created by the probe over the flat cathode surface is not uniform and depends on the exact distance d between the probe and the surface, the measured I-V characteristics are not directly interpretable. We present a methodology to transform the I(V) measurements into the corresponding current density J in function of actual field F for field emission, the (J-F) characteristics that must be used for any quantitative interpretations.