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Abstract

The electron cooler at the cryogenic storage ring CSR located at the Max Planck Institut f¨ur Kernphysik is used for ion beam phase space cooling, with the benefit of reaching a low ion energy spread relevant, e.g., for collision studies at conditions found in interstellar medium. The electron cooling quality is implied by the cooling force, which depends on various experimental parameters. In this thesis a phase-shift method for the electron cooling force measurement and electron cooling optimization is presented. It was successfully implemented and tested by recording data for four ion beam types: Xe³⁺, ArH⁺, HeH⁺ and Ne²⁺. The data was evaluated and the resulting cooling force curves were analysed for various systematic effects. Also a theoretical model to calculate the cooling force is given and the experimental results are compared with numerically calculated cooling force curves. The model was found to describe the experimental results well. Based on this work, the cooling force measurement is expected to become a routine optimization method in the CSR experiments involving electron beams.