The Behavior of Electrostatic Electron Multipliers as a Function of Frequency

This paper consists of a theoretical and experimental study of the frequency variation of transconductance of electrostatic electron multipliers. It is shown that the decrease of transconductance with frequency up to 500 megacycles, the highest frequency studied, can be ascribed to a spread in transit angle resulting from the emission velocities of secondary electrons and the varying paths of electrons through the stages of the multiplier. The spread in transit angle may be represented by an equivalent angle that is linearly related to the total transit angle unless the latter is quite large. For a given scale and with multipliers of the form herein studied an upper limit can be set upon the frequency at which multipliers may be profitably employed. A brief analysis of the effects of leads within the tube is included. An upper limit of 2X10^-9second was set upon the time taken for the phenomenon of secondary emission to occur.