Protonium x-ray spectroscopy

Preliminary results from the setup run of PS207 are reported. For the first time, antiprotonic x-rays were observed with a crystal spectrometer, and for the first time, strong-interaction effects in antiprotonic deuterium could be observed. It is shown that, for the performance of the cyclotron trap, crystal-resolution values close to the theoretical limit could be achieved. The pressure dependence of the Balmer series was measured from 1.3 to 30 mbar.