Comment on 'Electric field measurements under DC corona discharges in ambient air by electric field induced second harmonic generation'[Appl. Phys. Lett.115, 244101 (2019)]

摘要

Recently, Cui et al. reported results of the measurement of the electric field inside negative corona discharges in an axially symmetric wire-cylinder gap, performed using the modern electric field-induced second harmonic (E-FISH) diagnostics.1 Based on these results, it was concluded that the electric field at the wire surface is proportional to the current density of the corona discharge with a negative constant of proportionality or, in other words, appreciably decreases with increasing current, contrary to the classic Kaptzov assumption, which states that the steady state electric field at the conductor surface remains at the corona onset value. Note that this assumption can be traced back to the foundational work of Townsend of 1914 2 and is a cornerstone of the corona discharge theory.