Hahn and Straßmann had succeeded in splitting the uranium nucleus in 1938 using a weak source of radiation. But to increase the yields of decay products, the scientists had to switch to particle accelerators. Since the first particle accelerators were only available at other institutes, the KWI for Chemistry opted to purchase two particle accelerators while still in Berlin. However they never became operational there.
For various reasons, it was also not possible to construct the equipment in Tailfingen. But since Straßmann and, to an extent, Mattauch were interested in continuing the work in nuclear physics and radiochemistry, they set up a cascade generator in Mainz in 1949 and a Van de Graaff generator in 1960. This allowed them to create radioactive products for a variety of research purposes. A special building was constructed for the equipment which, because of its size, was nicknamed the ‘Giraffe Pen’.
Thanks to the mass spectrometer, which were greatly improved in Mainz, the Institute focussed primarily on nuclear physics and nuclear chemistry until the mid-1960s.
Today, the high-voltage cascade with ion tube is located in the outdoor area of the new MPIC building.