An R&D program for the research of 2$\beta$0ν decay with a SPC
Résumé
The objective of the R2D2 R&D is to test the concept of a spherical proportional counter (SPC) for the search of the neutrinoless double beta decay (2β0ν). For this, we built a small prototype (40 cm in diameter), which was filled with an argon-based gas mixture at pressures up to 1.1 bar, and irradiated with a $^{210}$Po alpha source. We report on results obtained in terms of directional, volume, and energy responses. We performed time measurements by combining the charge readout from the SPC with the light detection provided by a SiPM. We also studied the possibilities of localizing tracks in the detector and of discriminating multiple tracks.