ACTIONS
1997INTER ACTIONS
1997
Scientific Discoveries at Saxonburg
The Saxonburg cyclotron and a cyclotron at the University of Chicago had the highest energy pion beams in the world in the early 1950s. At Saxonburg Julius Ashkin and collaborators measured the scattering of pions from hydrogen and discovered a resonance that proved to be the first excited state of the proton. At the same time similar experiments were carried out by Enrico Fermi in Chicago. When negative pions are stopped in matter a new kind of atom can be formed in which the negative pion circulates about the nucleus. Sergio De Benedetti and his collaborators measured the x-rays from these exotic atoms for a whole series of nuclei. These spectra provide a beautiful example of atomic physics in a new domain and also provide important information on the pion-nucleus interaction.
