Several applications in modern nuclear physics, research and engineering are limited by a lack of precise knowledge in spectral shape data for beta-decays.Specifically the interest aims to study spectral data for forbidden decays with respectively long half-lives, which is one of the central activities of our group.For the investigation of greenlee 45300 those rare beta-decays the group operates a setup of six PIPS detectors in a vacuum chamber built out of low-radioactivity materials.
In the long term the setup will be used as low-background-detector for the investigation of rare beta-decays.In order to reduce the measuring-background a muon cougar bait shirt veto was installed.The characterization of the setup in the energy-range from 20.
1000 keV using conversion-electrons is described.A set of useful calibration-nuclides was established to determine energy calibration and efficiencies.