Radioactive Elements of Low Atomic Number
Radioactive elements of low atomic number have been produced by the transmutation of various elements from lithium to fluorine by high velocity deuterons. The distribution in energy of the electrons and positrons emitted by these elements has been determined by employing a Wilson cloud chamber traversed by a magnetic field. The electron spectra have been found to have maximum energies from 5 to 13 MEV while the positron spectra have maximum energies from 1 to 2 MEV. The form of the spectra has been found to be in agreement with a modification of the Fermi theory of beta-decay proposed by Konopinski and Uhlenbeck. The correlation of the maximum energies of the spectra with the energies calculated from the reactions in which the radioactive element is involved is shown to await a more accurate determination of the difference in mass between the neutron and proton.
©1936 The American Physical Society Received 21 February 1936 In conclusion we wish to express our appreciation to Dr. Robert Serber and Dr. J. R. Oppenheimer for discussions of the theoretical aspects of these investigations, to Kurie, Richardson and Paxton for sending us a copy of theur manuscript before publication, to Dean Woolbridge for preparation of the carbon targets containing an increased percentage of C13, and to Seeley W. Mudd fund for financial support.