Energy Distribution of Photoelectrons from Polycrystalline Tungsten

Total-energy distributions of the photoelectrons from aged polycrystalline tungsten ribbons, with the usual rolling texture, were determined by applying retarding potentials to spherical collectors. Particular attention was paid to the region of low energy. When stray fields were eliminated, energy-distribution functions rose linearly with energy. The average work function was determined by extrapolation of ${\mathrm{}\left(\mathrm{current}\right)\mathrm{}}^{\mathrm{½}}$-voltage curves to the saturation line. The result agreed with the value 4.49 ev determined both from the spectral distribution and from the temperature variation of the photo-current. Application of spherical photo-cells to investigations of semiconductors is discussed briefly.