1940/10/15 by Dale R. Corson, K. R. MacKenzie, E. Segrè · 4 citations
Physics and Astronomy · #Nuclear Physics and Applications #Radioactive Decay and Measurement Techniques #X-ray Spectroscopy and Fluorescence Analysis
paper · doi:10.1103/physrev.58.672
openalex publication_date 1940/10/15 · openalex created_date 2025/10/10 · openalex updated_date 2026/06/26
Bismuth bombarded with 32-Mev alpha-particles becomes radioactive. Two ranges of alpha-particles are emitted, one of 6.55 cm and one of 4.52 cm. These two alpha-particles are not genetically related. There are also x-rays which show the absorption characteristics of polonium x-rays. All these radiations separate together chemically as element 85, and all show the same half-life of 7.5 hours. The probable explanation of these effects is the following: Bi209, by an (\ensuremathα,2n) reaction, goes to 85211, which decays either by K-electron capture to actinium C'(Po211) or by alpha-particle emission (range 4.5 cm) to Bi207. The 6.5-cm alpha-particles are those of actinium C'. According to this scheme the second branch from 85211 leads to Bi207 which should decay to Pb207. As yet we have been unable to find this activity. We discuss the chemical properties of element 85 and show that in general its behavior is that of a metal.