Ion beam acceleration and new operation modes at the TSR Heidelberg

A newly designed radio frequency cavity was used at the storage ring TSR in Heidelberg to accelerate stored ¹²C⁶⁺ (E₀=73.3 MeV) beams. It was possible to accelerate about 90% of the stored particles by more than a factor of three in kinetic energy (E_fin ≈240 MeV). A new operating mode of the machine close to the transition energy was also investigated. Up to 10 μA ¹² C⁶⁺ and protons could be stored, however the beams were susceptive to longitudinal instabilities. For 21 MeV protons (γ=1.02) a γ_tr parameter of 1.04 could be reached. A new method to produce a beam of polarized ions, based on spin selective attenuation by a polarized atomic hydrogen target was successfully proved with 23 MeV protons. To minimize losses of the beam particles the TSR was operated in the low-beta mode. After one hour a beam polarisation of 0.014 was achieved