THE GERMANIUM WALL OF THE GEM DETECTOR SYSTEM

The GEM-detector system was developed to investigate meson production and meson-nucleus interaction with the external proton beam of the COS Y accelerator at Julich. GEM is a hybrid system consisting of the GErm anium Wall and the modified Magnetic spectrometer BIG KARL. The German ium Wall is a stack of up to four annular position-sensitive semicondu ctor detectors made from high purity germanium. Its design makes GEM a 4 pi-detector system for recoiling nuclei from reactions close to the production threshold [1]. In this contribution the design and the act ual status of the Germanium Wall is described.