Velocity of Electron Pulses

Abstract

ONE of us¹ has noted that the velocity of electrons has never been measured under conditions which allow no alternative interpretation. A linear velocity of displacement is a necessary inference only where two successive events, departure and arrival, have been observed which are localized and distinct, both in space and in time. In the known determinations with static or periodic deflecting fields one cannot discriminate between transit times of localized entities and vibration periods of extended systems. It appeared, therefore, of interest to determine the transit time, across a measured distance, of a brief pulse of electrons of known energy. This was achieved by using two deflector gates, which are opened for very brief intervals only by a single surge travelling in a cable, with an accurately measurable and adjustable delay time, corresponding to the length of cable, between the opening of the first gate and of the second.