FURTHER R&D FOR A NEW SUPERCONDUCTING CW HEAVY ION LINAC@GSI

A low energy beam line (1.4 MeV/u) behind the GSI High Charge State Injector (HLI) will provide cw-heavy ion beams with high beam intensity. It is foreseen to build a new cw-heavy ion LINAC for post acceleration up to 7.3MeV/u. In preparation an advanced R&D program is defined: The first LINAC section (financed by HIM and partly by HGF-ARD-initiative) comprising a sc CHcavity embedded by two sc solenoids will be tested in 2014/15 as a demonstrator. After successful testing the construction of an advanced cryo module comprising four CH cavities is foreseen. As an intermediate step towards an entire cw-LINAC the use of a double of two CHcavities is planned: A short 5 cell cavity should be mounted directly behind the demonstrator cavity inside a short cryostat. The design of the cw LINAC based on shorter sc CH-cavities would minimize the overall technical risk and costs. Besides with this cavity an optimized operation of the whole LINAC especially with respect to beam quality could be achieved. Last but not least the concept of continuous energy variation applying phase variation between the two cavities with constant beta profile could be tested.