A High Resolution Beta-Ray Spectrometer

Abstract

A relatively inexpensive 180° magnetic focusing beta‐ray spectrometer has been constructed, having a principle orbit radius of 15 cm. A radially inhomogeneous field provides essentially perfect focusing of electrons leaving the source within a 33° angle. In operation, with a 1‐mm wide source, the transmission is 0.2 percent, the full width at half‐maximum of an internal conversion line is 0.4 percent, and the effects of background and scattering are generally inappreciable.