Current Crowding in a Circular Geometry

Current crowding, a phenomenon well known in transistors, is discussed in terms of its importance in cold-cathode structures. The solution to the problem of current crowding in one dimension is reviewed, and the analogous problem for a device with circular symmetry is solved. The solution is presented in terms of a dimensionless parameter for two important cases having circular symmetry. It is shown that the solution of the circular problem approaches the solution of the one-dimensional problem in the limit of severe crowding.