A Source of Inaccuracy Encountered When Measuring Drift Velocities of Electrons in Gases by an Electrical Shutter Method

Abstract

In this paper attention is drawn to the precautions which must be adopted when the drift velocities of very slow electrons are to be measured by an electrical shutter method. While the experimental results (which for convenience were taken in hydrogen) show that quite serious errors may result at very low energies when the experimental conditions are unsuitably chosen, they also show that it is possible to reduce such errors to any required degree by appropriate choice of the parameters l and p. The form of the variation of the measured from the true values is in qualitative agreement with a formula given by R. A. Duncan when discussing diffusion in relation to measurements of this type.