Status of the Ion Source and RFQ Test Bench at the Heidelberg Ion Beam Therapy Centre

The possibility of cancer treatment with proton and carbon beams provides HIT (Heidelberg Ion Beam Therapy Centre) with an exceptional feature and gives it a unique position in Europe. In the future, the variety of available ions will be extended towards helium and oxygen. To allow fast switching between three of these ion species an additional ion-source / spectrometer combination will be installed in the LEBT. For comprehensive tests of the new components a dedicated test bench including a beam emittance analyser has been set up at the HIT facility. It opens up the opportunity to perform detailed investigations of the improved ECR ion source with its enhanced extraction system and the redesigned RFQ of the HIT injector. Parallel to the measurements, the beam optical model of the assembly could be refined to better reproduce the beam diagnostic results. Since August 2010 the test bench has been in operation in different configurations. Behind the RFQ a beamline comprising a phase-probe-based time-of-flight system and beam current measurement devices is set up. The aim is to determine the RFQ working point and to validate the optimisations in terms of particle transmission.