The Münster cluster target for internal storage ring experiments

The Münster cluster target has been built as a flexible device for internal storage ring experiments. To meet the particular spatial requirements of the COSY-ring at the KFA Jülich special cryopumps have been developed. Cluster beams of all gases except helium can be produced. Density profiles of the cluster beam can be measured on-line by means of a 5 keV electron scattering monitor system. An easy adaption of the cluster target to other installations is possible because of its compact modular design. During several beam times the target has successfully been operated within the COSY-11 experiment using hydrogen clusters. Cluster beam densities of up to p ∼ 1014 atoms/cm3 have been reached.