Realization of nanosecond antiproton pulses in the ultra-low energy storage ring

The international Facility for Antiproton and Ion Research (FAIR) at the GSI Helmholtz Centre for Heavy Ion Research in Germany is composed of a chain of accelerators and storage rings that will, amongst others, produce, store and slow down antiprotons with unprecedented beam characteristics. One of these rings, the Ultra-low energy electrostatic Storage Ring (USR), will provide cooled beams of antiprotons at energies as low as 20 keV with a small momentum spread of ∼10−4 and an emittance in the order of 1π mm mrad. d-beam atomic physics experiment that will allow, for the first time, to investigate into the collision dynamics of antiprotons with different target gases on the level of differential cross sections, require very short antiproton pulses of 1–2 ns duration. An “ultra-short pulse” operation mode was developed to enable these novel experiments. This paper describes two alternative schemes that were developed in the QUASAR Group and summarizes the changes required to enable the USR to operate in this mode.