When Lise Meitner left the Max-Planck-Institute for Chemistry in 1938, Otto Hahn hired Josef Mattauch (a specialist in mass spectrometry from the University of Vienna) to replace her. Mattauch had earlier analysed a Sr fraction which Hahn and his co-workers had separated from Canadian micas with high Rb and low Sr contents. Hahn wanted to know which of the two Rb isotopes is radioactive. He only knew that the element Rb is a β-emitter. Josef Mattauch could show that the Sr fractions from the Canadian micas were almost pure 87Sr by using the double focusing mass spectrometer, which he...

You do not currently have access to this article.