Read-Out and Electrical Connection of Modern High-Purity Germanium Detectors: Innovative Flexible Systems and Integrated Charge-Sensitive Pre-amplifiers

Segmented high-purity germanium detectors are at the heart of cutting-edge gamma spectroscopy. However, their technical and manufacturing specifications are not known, since they are provided by industry. To bridge this gap, Italy’s INFN launched the N3G Project, an initiative to design new segmented high-purity germanium detectors while acquiring the technical expertise to build, manage, and maintain them independently. In this framework, the current paper offers a novel contribution. The innovative system designed to electrically connect the electrodes of the detector to the front-end electronics will be described and its low impact on the detector leakage current will be shown. Moreover, the architecture of a new integrated charge sensitive pre-amplifier will be reported and its validation will be presented. The circuit demonstrated excellent linearity and low noise. An integral non-linearity factor of $\mathbf{0. 4} \%$ was found and an optimum equivalent noise charge of 108 root-meansquare electrons was measured for a 15 pF equivalent electrode capacitance.