XXI. The focusing of β-rays in a prolate spheroidal magnetic field

Abstract

Summary A discussion is given of the applicability to β-ray spectroscopy of the magnetic field between pole-faces which are hyperboloids of revolution. Trajectories of particles emitted from points on the axis of symmetry are computed by numerical integration of the relativistic equations of motion. The rays have the property of crossing over at two successive sites in the meridional plane of which the second could be arranged to lie close to the axis. The attainable resolving power seems to be similar te that ()f the semicircular spectrograph, while the solid angle of collection can be nmde as large as 8.5 per cent of 4π.