Electrode Design for Testing in Uniform Field Gaps

The efficiency of producing uniform fields in the test gap was evaluated for practical electrode configurations corresponding to the plane, the Rogowski and the Bruce profiles. The field intensity was calculated using the known charge simulation method and the calculated distributions of the field intensity at the surface of different electrode configurations were compared. The results obtained show a pronounced end effect at plane-profile electrodes. With the Rogowski profile, the effective uniform-field region is dependent on the gap spacing. The Bruce profile was found to be a good compromise, with a negligible end effect and a nearly constant uniform field region. Practical considerations are also presented together with the limitations of various profile configurations in the design of uniform field electrodes.