An ultra-low-energy storage ring at FLAIR

The future accelerator Facility for Antiproton and Ion Research (FAIR) at GSI, Darmstadt will produce the highest flux of antiprotons in the world. So far it is foreseen to accelerate the antiprotons to high energies (3-15 GeV) for meson spectroscopy and other nuclear and particle physics experiments in the High-Energy Storage Ring (HESR). Within the planned complex of storage rings, it is possible to decelerate the antiprotons to about 30 MeV kinetic energy, opening up the possibility to create low-energy antiprotons. In the proposed Facility for Low-energy Antiproton and Ion Research (FLAIR) [http://www.flair.eu.tt] the antiprotons shall be slowed down in a last step from 300 to 20 keV in an ultra-low-energy electrostatic storage ring (USR) for various in-ring experiments as well as for their efficient injection into traps. This paper presents the layout and design parameters of the USR.