The velocity distribution of β-particles after passing through thin foils

Abstract

When a parallel beam of β-particles, homogeneous in velocity, falls upon a sheet of matter not thick enough to obstruct it completely, the stream which emerges consists of particles which in general have suffered both a loss of velocity and a change in direction of motion. The investigation of this action accordingly falls into two parts, one directed to examining the changes in direction of motion of the particles, or scattering of the beam, the other to measuring their loss of velocity. This paper is devoted to the second of these problems.