The β-ray spectrum of mesothorium 2

Abstract

In recent years much attention has been directed to the detailed study of the magnetic β-ray spectra of some of the radioactive bodies, since the lines in these β-ray spectra have been shown to be due to the quantum conversion of γ-rays into β-rays in their passage through the ordinary electronic structure of the atom. There is strong evidence that these γ-rays have their origin in the nucleus, and the frequency of some of them can be deduced from a study of the β-ray spectrum. Attention has been paid mainly to the radioactive elements radium B and radium C, as strong sources of these elements can be obtained by exposure to radium emanation. In particular, Ellis and Ellis and Skinner have analysed in detail the β-ray spectra of these elements, and have shown that the γ-rays from the nucleus can be accounted for as being due to transitions in a system of levels, indicating that the quantum dynamics is applicable to the nucleus.