Surface characterisation of Germanium detectors

Germanium-detectors are the most sensitive high-resolution γ detectors available and are the instrument in nuclear structure physics which allows important information about the structure of atomic nuclei to be obtained. The technology of High purity Germanium detectors is presented in [1]. The reported work is motivated by the needs for a new mechanical treatment procedure within the manufacturing methods in order to obtain better quality of the Germanium surfaces and increased cost-efficiency. Seven germanium crystals with different surface qualities due to varying mechanical treatment were employed for the characterisation of their surfaces. Five of the crystals were fully processed to obtain working detectors. In a first step surfaces were investigated with a Scanning Tunnelling Microscope and a Profiler. The crystals have a size of 8×8×10 mm and are fixed in special housings. A Germanium crystal installed in its housing is shown in Figure 1. These housings are optimized for all used microscopes as well as for a newly developed detector cryostat.