GeDet Measurement Program
One goal of the GEDET group was to prove that segmented germanium detectors do work when submerged in a cryogenic liquid and to develop procedures to safely doing so. This was possible, details here [pdf] [ps], through the development of increasingly sophisticated test facilities, details here [pdf] [ps].
This was one requirement for a possible usage of segmented detectors in large experiment like GERDA.
Most of the work was done on n-type detectors. Segmented n-type detectors are only used in a few experiments. The technology can only be provided by one supplier, Canberra France, and the detectors are custom made for each experiment. Therefore, the characteristics of the 18-fold segmented detectors chosen needed to be investigated, details here [pdf] [ps].
The detailed measurements performed needed to be accompanied by Monte Carlo simulations in order to facilitate complete analyses. The groups used existing Monte Carlo packages and added another specialised package, details here [pdf] [ps].
Using data from various test facilities and the Monte Carlo, a number of analyses were completed:
Photon interactions were studied in several analyses, details here [pdf] [ps].
Segmented detectors were shown to be a powerful tool to identify photon induced interactions and thus reduce the background for a neutrinoless double beta experiment like GERDA.
Neutron interactions were studied in another, particularly interesting analysis, details here [pdf] [ps].
It was possible to resolve the event topologies of neutron neutron interaction, and especially measure the recoil spectra.