Secondary processes active in the electrical breakdown of gases

Recent advances in techniques and consequent results indicate the complexity of gaseous breakdown mechanisms. The three cathode mechanisms and two anode mechanisms are carefully analysed indicating their relative importance and conditions of appearance. They are shown to lead to the same type of generalized breakdown threshold condition with statistical fluctuations and subject to alteration by space charges. This condition masks the processes active rendering analysis difficult. The threshold mechanisms alone do not determine the breakdown for this involves the ultimate resulting discharge. The factors modifying the discharge are gas type and state, electrodes, geometrical factors and external circuit constants. The discharge types to which these lead and governing circumstances are presented. In conclusion proper modern methods of discharge analysis are indicated.