Effect of a virtual cathode on the I-V trace of a planar Langmuir probe

Experimental and modelling studies were performed to investigate how the presence of a virtual cathode (Forest and Herschkowitz 1986 J. Appl. Phys. 60 1295) near a planar Langmuir probe affects its accuracy in electron temperature measurements. It is found that the effect of the virtual cathodes causes the I-V trace to flatten and falsely create higher electron temperature measurements.