10-12 April 2013
INFN - Laboratori Nazionali del Gran Sasso
Europe/Rome timezone

Low background HPGe spectrometer in investigations of 2β decay

11 Apr 2013, 15:00
1h 20m
E. Fermi auditorium (INFN - Laboratori Nazionali del Gran Sasso)

E. Fermi auditorium

INFN - Laboratori Nazionali del Gran Sasso

SS 17 bis, km 18 + 910, 67100 Assergi (AQ), Italy
poster Screening facilities and low background detectors Poster session

Speaker

Ms Ekaterina Rukhadze (Institute of Experimental and Applied Physics CTU, Prague)

Description

To search for double beta decay processes to the excited states of daughter nuclei, such as resonant 0νEC/EC decay of 106Cd (TGV experiment) and 2ν2β- decay of 100Mo (NEMO-3 experiment) to the 0+ (1130 keV) and 2+ (540 keV) excited states of 100Ru, a low background HPGe spectrometer Obelix with sensitive volume of 600 cm3 and efficiency of ~160% was installed at the Modane Underground Laboratory (LSM, France, 4800 m w.e.), as a common activity of JINR-IEAP CTU-LSM (details of the spectrometer will be presented by P.Loaiza). Such types of investigations are based on analyzing of γ-rays emitting in de-excitation of the excited states of daughter nuclei. The sensitivity of the Obelix spectrometer for 2β measurements is higher than T1/2 ~10^21 years. To obtain the detector efficiency for such measurements the original method of using special low-active samples with known mass and activity was developed. The samples were produced from the powder of La2O3. The natural La in this powder consists of ~0.09% of 138La (T1/2=1.02×10^11 years), which is characterized by emission of γ-rays with energies of 788.7 keV and 1435.8 keV. Based on the results of measurements of La2O3 and standard sources of 152Eu and 133Ba, efficiency curves for the measurements of double beta emitters were obtained. Metallic foil of enriched 100Mo with a mass of 2517 g was measured with the Obelix spectrometer for 2288 hours. From this measurement the contamination of 100Mo foil (radioactive isotopes and their activities) as well as half-life of 2ν2β- decay of 100Mo to the 0+ and 2+ excited states of 100Ru were obtained. The preliminary results will be presented.

Primary author

Ms Ekaterina Rukhadze (Institute of Experimental and Applied Physics CTU, Prague)

Presentation Materials

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