Mevva development for the new GSI high-current injector

To increase the intensity of the heavy ion synchrotron SIS for heavy elements by a factor of ∼50, a new prestripper accelerator is planned for Unilac and the heavy ion synchrotron SIS. It is designed to accept ions with mass/charge ≤ 65 and an injection energy of 2.2 keV/u. A vacuum arc ion source with a strong axial magnetic field will deliver 15 mA of U4+ as heaviest element at a repetition rate of 1 Hz and a pulse length of 300 μs. The investigation of the Mevva ion source with pulsed magnetic field of several kGauss have shown that ion currents of 8 mA U4+ can be measured at the authors test bench after 5m of transport and charge analysis (transmission at the test bench 25% only). The noise on the extracted ion beam was already ≤25%, a value similar to the Pig ion source in the sputter mode, but efficient high current beam transport probably requests further improvements