Selection criteria for 2$\nu$2$\beta$-decay measurements with the COBRA experiment

The COBRA collaboration searches for the neutrinoless double beta-decay (0$\nu$2$\beta$-decay). This process is forbidden in the Standard Model of particle physics due to the lepton-number violation. Currently a demonstrator setup using coplanar-grid CdZnTe detectors is operated at the underground facility LNGS in Italy. The setup consists of 64 detectors, each with a volume of 1 cm${}^3$, arranged in four layers of 4$\times$4 detectors. The CdZnTe semiconductor crystals contain nine double-$\beta$ isotopes with several possible decay modes. The main focus is on ${}^{116}$Cd due to its high Q-value of 2813 keV. Besides the effort to search for the 0$\nu$2$\beta$-decay the 2$\nu$2$\beta$-spectrum of the normal double-decay should be measured to confirm half-life measurements of other groups. The most promising 2$\nu$2$\beta$-decays are coming from ${}^{116}$Cd and ${}^{130}$Te which have not been measured yet by the COBRA experiment itself. This talk will focus on different selection criteria with the aim to identify run periods and detectors with a high background index. Such a data partitioning will improve the background understanding since one data sample will be background enriched while the other results in a cleaner spectrum. Combining both information will be beneficial for the intended 2$\nu$2$\beta$-decay analysis of ${}^{116}$Cd with the COBRA demonstrator.