Collision spectroscopy of highly charged ions at the ESR storage ring

With the advent of the relativistic storage ring ESR, a new generation of highly precise collision experiments has become accessible even for the heaviest ion species. At the ESR, the interaction of brilliant beams of cooled high-Z ions with low-dense gaseous matter can be studied without any beam collimation guaranteeing background-free experimental conditions. Furthermore, a unique feature of the ring is its capability to decelerate even bare uranium ions to moderate energies close to about 10 MeV/u i.e. it allows to scan the beam energies from highly relativistic encounters to almost slow collisions. Currently, the main experimental activities focus on final state resolved electron capture, photon angular distribution and alignment investigations.