Image credit: Gaby Otto/GSI.
Elaborate alterations to the Schwerionensynchrotron (SIS) – the heavy-ion synchrotron at GSI – have finished after one year’s work. The main new feature is an additional accelerator cavity, so that the accelerator now has a total of three cavities. The remodelling of the SIS accelerator was necessary for it to serve in future as an injector for the Facility for Antiproton and Ion Research (FAIR). The FAIR accelerator complex, which is currently under construction through an international effort, will be connected to the existing GSI facility.
The SIS accelerator has a circumference of 216 m, with about 50 magnets – each weighing several tonnes – to keep the particles on the correct path. In the coming years, two further accelerator cavities will be added. With a total of five cavities, the SIS will have the performance that is required to accelerate all kinds of elements and inject them into the FAIR machines.
Since its commissioning in 1990, SIS has been the scene of many successes, including the discovery of hundreds of new isotopes – a field in which a GSI scientist holds the world record – and three new types of radioactive decay. Work on SIS in biophysics also led to the development of ion-beam therapy at GSI, where 450 patients were successfully treated. This method of cancer therapy is now routinely administered at the HIT facility in Heidelberg, using a dedicated accelerator built by GSI.
