Search

The main goal of this project was the improvement of the energy resolution of the scintillating detectors. In order to obtain the required energy resolution at the level of ∼ 8 %, which corresponds to the half-life sensitivity of about 1.2 × 1026 years for the SuperNEMO experiment [1], an optimal ratio of concentrations of the activator (pTP) and the wavelength shifter (POPOP) in the purified polystyrene (PS) base had to be found. Furthermore, good optical properties and mainly the energy resolution for such improved detectors are comparable with properties for higher price plastic scintillators based on the polyvinyltoluene (PVT). In this contribution, the results of the measurement with the organic plastic scintillators with various composition are presented.

International audience; A new experimental run of searching for EC/EC decay of Cd-106 was performed at the Modane underground laboratory (4800 m w.e.) using the TGV-2 spectrometer and similar to 23.2 g Cd-106 with enrichment of 99.57%. The limit on 2 nu EC/EC decay of Cd-106 -T-1/2(2 nu EC/EC) > 3.1x10(20) y, at 90% C. L was obtained from the preliminary calculation of experimental data accumulated for 7018 h of measurement. The limits on the resonance neutrino-less double electron capture decay of Cd-106 were obtained from the measurement of similar to 23.2 g of Cd-106 with the low-background HPGe spectrometer OBELIX lasted 395 h -T-1/2(KL, 2741 keV) > 0.9x10(20) y and T-1/2(KK, 2718 keV) > 1.4x10(20) y at 90% C.L.

Investigations of double beta decay processes to excited states of daughter nuclei were performed at the Modane underground laboratory (LSM, France, 4800 m w.e.) using the high sensitivity spectrometer OBELIX [1], which is a common activity of JINR Dubna, IEAP CTU in Prague and LSM. The spectrometer is based on the HPGe detector with the sensitive volume of 600 cm3 and relative efficiency of 160%. Investigation of resonant neutrino-less double electron capture of 106Cd was performed with ∼23.2 g of 106Cd (enrichment of 99.57%) during ∼17 days. The experiment with natural Ni (∼21.7 kg of mass) was also carried out during ∼47 days. The preliminary experimental limits for 0νEC/EC resonant decay to the excited states of 106Pd and different modes of β β decay 58Ni are presented.

The hunt for the neutrino mass in the process of the neutrinoless double beta decay (0νβ β) belongs to a crucial task in the field of physics beyond the Standard model. The next generation experiment SuperNEMO, based on the NEMO-3 calo-tracko detection technique is devoted to measure this extremely rare nuclear process within the half-life sensitivity T1/20v of 1 × 1026 years, which correspond to the sensitivity on the effective neutrino mass 〈mν〉 of 40 – 110 meV. In this contribution, a progress in the construction and commissioning of the first SuperNEMO module - demonstrator, is reported.