Light Emission from Polonium

Abstract

THE visible spectrum of light emitted from a sample of polonium has been photographed using the night-sky spectrograph designed by McLennan and Ireton¹. The activity of the sample was about 4 mC., and it was deposited on a platinum sheet, 3 mm. × 3 mm. This shape was chosen for another purpose and is not very suitable for a spectral investigation. The night-sky spectrograph contains a glass prism and, therefore, its application is restricted to the visible range. The aperture is f/l. The slit-width used in this investigation was 0.4 mm. The polonium sample was put in two positions with respect to the slit of the spectroscope: (1) the surface of the sample was in the plane of the slit parallel to the collimator axis so that light emitted from the surface could enter the slit; (2) the surface was about 1 mm. below the slit, so that only light emitted from the volume of ionized gas (air) above the surface could enter the slit.