STATUS OF THE HZB CYCLOTRON

The therapy of ocular melanomas in Berlin started 1998 as cooperation between the Benjamin-Franklin Klinikum (now Charite) and the Hahn-Meitner-Institut (now Helmholtz-Zentrum Berlin). More than 2222 patients have been treated since. The facility is still the only facility in Germany treating ocular melanomas with protons. In the beginning, tumour therapy used about 10 % of the overall beam time and its accelerator operation was embedded in the operation for physics experiments. The end of the physics programme in 2006 had severe consequences: Beam time, and consecutively funds and resources, were cut-down remarkably. The accelerator operation continued mainly for therapy since 2007 with reduced man-power, requiring changes in the set-up and operation regime of the accelerators. Maintaining a high reliability is a key issue. The stability of the proton beam is of utmost importance for the therapy, both on the short-term and the long-term scale. ACCELERATORS AND OPERATION