IEAP - Institute of Experimental and Applied Physics CTU - Czech Technical University in Prague
Česky English
IEAP - Institute of Experimental and Applied Physics CTU - Czech Technical University in Prague
CTU - Czech Technical University in Prague
Partial tasks  > NEMO 3
NEMO 3

The NEMO 3 experiment (NEMO = Neutrino Ettore Majorana Observatory) is devoted to the search for neutrinoless double beta decay (0νββ) and to the accurate measurement of two-neutrino double beta decay (2νββ). For this goal, the experiment combines two detection techniques: calorimetry and tracking. Such approach allows us at the same time unambiguous identification of e, e+, γ, and α-particles provided by a wire tracking chamber and energy and time measurements of particles with a calorimeter.
The NEMO 3 detector is installed and currently running in the Fréjus Underground Laboratory (4800 m w.e.) in France. The experimental set-up is cylindrical in design, is divided into twenty equal sectors and with γ and neutron shielding it has about 6 m in diameter and 4 m in height.
The tracking wire chamber is made of 6180 open octagonal drift cells operating in Geiger mode (Geiger cells). It is filled with a gas mixture of 95% He, 4% ethyl-alcohol and 1% Ar. The Geiger cells provide a three-dimensional measurement of the charged particle tracks by recording the drift time and the two plasma propagation times.
The calorimeter, which surrounds the wire chamber, is composed of 1940 plastic scintillators coupled by light-guides to very low-radioactivity PMTs. The energy resolution σE/E of the calorimeter ranges from 6.0% to 7.5% for 1 MeV electrons, while the time resolution is 250 ps.
Seventeen sectors of NEMO 3 accommodate almost 10 kg of the following, highly enriched (95% – 99%) ββ decay isotopes: 100Mo (6914 g), 82Se (932 g), 116Cd (405 g), 130Te (454 g), 150Nd (34 g), 96Zr (9 g), and 48Ca (7 g). In addition, three sectors are also used for external background measurement and are equipped with pure Cu and natural Te. All these isotopes are produced in the form of thin foils and are placed in the central vertical plane of each sector.
For the e / e+ recognition, the detector is surrounded by a solenoidal coil which generates a vertical magnetic field of 25 Gauss. Moreover, NEMO 3 is covered by two types of shielding against external γ-rays and neutrons. Finally, the whole experimental set-up is closed inside a “tent”, which is supplied with radon-free air from a radon trapping facility. Radon is trapped and then decays inside a tank filled with 1 ton of charcoal (K48 from Silicarbon Aktivkohle) cooled down to −50˚C. This facility decreases the radon level of the air from the laboratory (15 – 20 Bq/m3) by a factor of ~1000. The radon trapping facility has been operating in the laboratory since October 2004.

Official web page of the NEMO 3 experiment.



Responsible person

Co-workers

Grants:
Number Name Agency
80-04005 ILIAS - Integrated Large Infrastructures for Astroparticle Sciences EU FP6
80-04005 ILIAS - Integrated Large Infrastructures for Astroparticle Sciences EU FP6
202/05/P293 Measurement of double beta decay of 100Mo and 116Cd in the NEMO 3 experiment GAČR
CTU 0708414 Measurement of low Rn concentration and diffusion in underground experiments CTU


Articles in Impacted Journals
(10)
Text format
Year

Ocenění Name Author Scientific journal OceněníYear
Arbitrary mass Majorana neutrinos in neutrinoless double beta decay Faessler A.; Gonzales M.; Kovalenko S.; Šimkovic F. Phys. Rev. D 90, 096010 2014
Chiral two-body currents and neutrinoless double-β decay in the quasiparticle random-phase approximation Engel J.; Šimkovic F.; Vogel P. Phys. Rev. C 89, 064308 2014
Neutrino propagation in nuclear medium and neutrinoless double-beta decay. Kovalenko S.; Krivoruchenko M.; Šimkovic F. Phys. Rev. Lett. 112, 142503 2014
Possibility of measuring the CP Majorana phases in neutrinoless double-beta decay Šimkovic F.; Bilenky S.; Faessler A.; Gutsche T. Phys. Rev. D 87, 073002 2013
Measurement of double beta decay of 100Mo to excited states in the NEMO 3 experiment Arnold R.; Augier C.; Vála L.; Jerie J.; Štekl I.; Vorobel V.; NEMO Collaboration Nucl. Phys. A 781 (2007) pp. 209-226 2007
Limits on different majoron decay modes of 100Mo and 82Se for neutrinoless double beta decays in the NEMO-3 experiment Arnold R.; Augier C.; Vála L.; Štekl I.; Vorobel V.; NEMO Collaboration Nuclear Physics A 765 (2006) 483-494 2006
First results of the search for neutrinoless double beta decay with the NEMO 3 detector Arnold R.; Augier C.; Vála L.; Štekl I.; Vorobel V.; NEMO Collaboration Phys. Rev. Lett. 95 (2005) 182302 2005
Technical design and performances of the NEMO 3 detector Arnold R.; Augier C.; Vála L.; Štekl I.; Vorobel V.; NEMO Collaboration NIM A 536 (2005) 79-122 2005
Study of 2β decay of 100Mo and 82Se using the NEMO 3 detector JETP Letters 80 (2004) pp. 377-381 2004
Possible background reduction in double beta decay experiments Arnold R.; Augier C.; Vála L.; Štekl I.; Vorobel V.; NEMO Collaboration Nucl. Inst. and Meth. in Phys. Res A 503 (2003) pp. 649-657 2003
Search
10th Anniversary of IEAP