The Diamond Project at Gsi - Perspectives

Heavy-ion experiments at GSI cover nuclear and atomic physics, related basic and applied research in plasma physics and material science as well as biophysics including tumor therapy with carbon ions. After low-energy sections, the heavy-ion synchrotron (SIS) provides pulsed, cooled ion beams up to 2 GeV/amu of beam intensities up to 10 ions/spill. All kind of ions from protons with Z=1 to U ions with Z=92 are available. Detector and trigger systems have to cope with a signal ratio of 1:9000, a variable beam intensity from a few ions to about 10 ions/s and a time structure from 100 ns to 10 s. Whereas the high-energetic ions from the SIS traverse nearly undisturbed the detectors, in the low-energy domain of the accelerator facility the ion range in solid state material is in the order of 1 m. Severe radiation damage is observed. The most remarkable properties of CVD-diamond detectors implemented in heavy-ion measurements at GSI are radiation hardness, intrinsic time resolution well below 50 ps and a single-particle count-rate capability ranging from 1 to 10 ions/s . However, due to the inhomogeneous charge collection inside the polycrystalline diamond bulk, even a rough particle identi cation based on pulse-height resolution is excluded .