On the stability of strong double layers

Abstract

For a strong, stationary double layer to be maintained, the electron flux Φe and the ion flux Φi must satisfy the Langmuir condition Φe/Φi = √mi/me. However, this condition alone does not determine whether or not the double layer will remain in stable equilibrium at a given position. A new stability condition is obtained and the results of several laboratory double layer experiments are examined using this condition.