Physics with Ge-miniball-arrays

For the measurement of rare gamma decays with low gamma-ray multiplicities (M-gamma < 15) dedicated Ge-detector arrays are being developed. They are optimized with respect to the full-energy peak efficiency rather than the resolving power. These so-called miniball arrays will pre dominantly be used at radioactive ion beam facilities. The detector arrays will have a high granularity using segmented Ge-detectors to provide a sufficient angular resolution of the gamma rays which is needed for proper Doppler-shift corrections and small Doppler-broadening. We will describe shortly the MINIBALL presently developed by a German, Belgian, and Italian collaboration and the wide range of physics to be addressed with this new detector system.