Inception of positive wire-cylinder corona discharges in air in crossed electric and magnetic fields

Abstract Computational study of inception of positive wire-cylinder corona discharges in low-pressure air in crossed electric and magnetic fields is performed. The inception voltages are calculated for a wide range of gas densities, wire radii and applied magnetic fields. Conditions are considered when the reduced electric fields at wire electrodes reach extremely high values, of about 10 kTd. Expression, applicable at such strong fields, for the ionization coefficient, the key parameter of the corona inception model, is presented versus the values of electric and magnetic fields. Calculated inception voltages agree with a number of available experimental data on low-pressure positive corona discharges, obtained both with and without application of magnetic fields. Results of calculation describe specific details of non-monotonous dependence of the inception voltages on the magnetic field values, similar to those obtained in experiments.