Discharge phenomena in gases

O D U C T I O N o R reasons not unconnected with the war.the present Report deal9 with only three sections of the field, and seeks to give a critical summary of F the present trend of thought without attempting to refer to all the relevant contributions.It attempts to extend the consideration of these sections given in the reviews of Druyvesteyn and Penning (1940) and of Francis and Jenkins (1 940).0 2 (by R. W. L.) deals with the statistical theory of reactions in gases maintained in a state of partial ionization, and with the implications of this theory to the general understanding of the mechanism of discharges for which the kinetics of the simplei onization reaction by electron impact are of particular importance.$ 3 (by A. v. E.) is concerned with the mechanism of the negative zones in glow discharges, especially with the factors controlling the cathode fall of potential ; in this the absolute value of the velocity coefficient of the simple ionization reaction is a matter of moment.$ 4 (by J. 31.M.) deals with the mechanism of the rapidly changing phases of partial ionization which culminate in a spark ; and here again the same reaction is of prime importance in the interpretation of the observed phenomena.