1. NEMO-3 Experiment Neutrino Ettore Majorana Observatory
RESULTS OF NEMO3 & SUPERNEMO
Laurent Simard 1
for the
NEMO-3 Collaboration
CENBG, IN2P3-CNRS et Université de Bordeaux, France
Charles University, Praha, Czech Republic
CTU, Praha, Czech Republic
FES University, Morocco
INEEL, Idaho Falls, USA
IReS, IN2P3-CNRS et Université de Strasbourg, France
ITEP, Moscou, Russia
JINR, Dubna, Russia
Jyvaskyla University, Finland
Kharkov University, Ukrain
1 LAL, IN2P3-CNRS et Université Paris-Sud, France
LSCE, CNRS Gif sur Yvette, France
LPC, IN2P3-CNRS et Université de Caen, France
Manchester University, United Kingdom
Mount Holyoke College, USA
University of Osaka, Japan
RRC Kurchatov Institute, Moscow, Russia
Saga University, Saga, Japan
University of Texas, USA
UCL, London, United Kingdom
Laurent Simard for the NEMO-3 Collaboration WIN 05 Delphi June 2005

2. Plan of the talk:
Results of NEMO-3 experiment
NEMO-3 Detector
Measurement of bb2n decay for several nuclei
Search for bb0n decay with 100Mo and 82Se
Description of future projects
The SUPERNEMO project
other projects

3. Fréjus Underground Laboratory : 4800 m.w.e.
The NEMO3 detector
3 m
4 m
B (25 G)
20 sectors
Fréjus Underground Laboratory : 4800 m.w.e.
Magnetic field: 25 Gauss
Gamma shield: Pure Iron (e = 18 cm)
Neutron shield: 30 cm water (ext. wall)
40 cm wood (top and bottom)
(since march 2004: water + boron)
Source: 10 kg of  isotopes
cylindrical, S = 20 m2, e ~ 60 mg/cm2
Tracking detector:
drift wire chamber operating
in Geiger mode (6180 cells)
Gas: He + 4% ethyl alcohol + 1% Ar + 0.1% H2O
Calorimeter:
1940 plastic scintillators
coupled to low radioactivity PMTs
Able to identify e-, e+, g and a
Laurent Simard for the NEMO-3 Collaboration WIN 05 Delphi June 2005

4. PMTs scintillators Cathodic rings Wire chamber Calibration tube
bb isotope foils
Laurent Simard for the NEMO-3 Collaboration WIN 05 Delphi June 2005

5. AUGUST 2001
Laurent Simard for the NEMO-3 Collaboration WIN 05 Delphi June 2005

6. Start taking data 14 February 2003
NEMO-3 Opening Day, July 2002
Start taking data 14 February 2003
Water tank
wood
coil
Iron shield
Laurent Simard for the NEMO-3 Collaboration WIN 05 Delphi June 2005

7. bb decay isotopes in NEMO-3 detector
bb2n measurement
116Cd g
Qbb = keV
96Zr g
Qbb = 3350 keV
150Nd g
Qbb = keV
48Ca g
Qbb = 4272 keV
130Te g
Qbb = 2529 keV
External bkg
measurement
100Mo kg
Qbb = 3034 keV
82Se kg
Qbb = 2995 keV
natTe g
Cu g
bb0n search
(All the enriched isotopes produced in Russia)
Laurent Simard for the NEMO-3 Collaboration WIN 05 Delphi June 2005

8. bb events selection in NEMO-3
Deposited energy:
E1+E2= 2088 keV
Internal hypothesis:
(Dt)mes –(Dt)theo = 0.22 ns
Common vertex:
(Dvertex) = 2.1 mm
Vertex
emission
(Dvertex)// = 5.7 mm
Transverse view
Longitudinal
view
Run Number: 2040
Event Number: 9732
Date:
Criteria to select bb events:
2 tracks with charge < 0
2 PMT, each > 200 keV
PMT-Track association
Common vertex
Internal hypothesis (external event rejection)
No other isolated PMT (g rejection)
No delayed track (214Bi rejection)
bb events selection in NEMO-3
Typical bb2n event observed from 100Mo
Transverse view
Run Number: 2040
Event Number: 9732
Date:
Longitudinal
view
100Mo foil
100Mo foil
Geiger plasma
longitudinal
propagation
Drift distance
Scintillator
+ PMT
Trigger: PMT > 150 keV
3 Geiger hits (2 neighbour layers + 1)
Trigger rate = 7 Hz
bb events: 1 event every 1.5 minutes
Laurent Simard for the NEMO-3 Collaboration WIN 05 Delphi June 2005

9. 2e- event e-Neventto measure l  
e+ – e- pair event B rejection 
 -  (delay track) event 214Bi  214Po  210Pb

10. Expected Performance of the detector
Time Of Flight:
Time Resolution (bb channel)  250 ps at 1 MeV
ToF (external crossing e- ) > 3 ns
external crossing e- totaly rejected
External Background
bb events from the foil
(Dtmes – Dtcalc) external hypo. (ns)
(Dtmes – Dtcalc) internal hypo. (ns)
Calorimeter:
97% of the PMTs+scintillators are ON
Energy Resolution:
calibration runs (every ~ 40 days) with 207Bi sources
17%
14%
FWHM (1 MeV)
Int. Wall
3" PMTs
Ext. Wall
5" PMTs
207Bi
2 conversion e-
482 keV and 976 keV
482 keV
976 keV
FWHM = 135 keV
(13.8%)
Daily Laser Survey to control gain stability of each PM
gamma: efficiency ~ keV, Ethr = 30 keV
Tracking Detector:
99.5 % Geiger cells ON
Vertex resolution:
2 e- channels (482 and 976 keV) using 207Bi sources
at 3 well known positions in each sector
s (DVertex) = 0.6 cm
s// (DVertex) = 1.3 cm (Z=0)
e+/e- separation with a magnetic field of 25 G
~ 3% confusion at 1 MeV b-
DVertex
DVertex = distance between the two vertex
Expected Performance of the detector
has been reached
Laurent Simard for the NEMO-3 Collaboration WIN 05 Delphi June 2005

11. Measurement of 2b2n decay
in NEMO-3
Laurent Simard for the NEMO-3 Collaboration WIN 05 Delphi June 2005

12. 100Mo 22 preliminary results
(Data 14 Feb – 22 Sep. 2004)
Sum Energy Spectrum
Angular Distribution
NEMO-3
events
6914 g
389 days
S/B = 40
NEMO-3
events, S/B =40
6914 g, 389 days
100Mo
100Mo
Data
22
Monte Carlo
Data
Background
subtracted
22
Monte Carlo
Background
subtracted
7.37 kg.y
T1/2 = 7.11 ± 0.02 (stat) ± 0.54 (syst)  1018 y
Laurent Simard for the NEMO-3 Collaboration WIN 05 Delphi June 2005

13. 22 preliminary results for other nuclei
NEMO-3
932 g
241.5 days
2385 events
S/B = 3.3
Background subtracted
82Se
82Se T1/2 = 9.6 ± 0.3 (stat) ± 1.0 (syst)  1019 y
116Cd T1/2 = 2.8 ± 0.1 (stat) ± 0.3 (syst)  1019 y
150Nd T1/2 = 9.7 ± 0.7 (stat) ± 1.0 (syst)  1018 y
96Zr T1/2 = 2.0 ± 0.3 (stat) ± 0.2 (syst)  1019 y
NEMO-3
405 g
168.4 days
1371 events
S/B = 7.5
NEMO-3
37 g
168.4 days
449 events
S/B = 2.8
NEMO-3
5.3 g
168.4 days
72 events
S/B = 0.9
116Cd
150Nd
96Zr
Data
Data
Data
bb2n
simulation
bb2n
simulation
bb2n
simulation
E1+E2 (MeV)
E1+E2 (MeV)
E1+E2 (MeV)
Laurent Simard for the NEMO-3 Collaboration WIN 05 Delphi June 2005

14. Search for 2b0n decay in NEMO-3
Laurent Simard for the NEMO-3 Collaboration WIN 05 Delphi June 2005

15. bb0n Analysis: Background Measurement
NEMO-3 can measure each component of its background !
External Background 208Tl (PMTs)
Measured with (e-, g) external events
~ 10-3 bb0n-like events year-1 kg -1 with 2.8<E1+ E2<3.2 MeV
External Neutrons and High Energy gamma
Measured with crossing e- or (e-,e+)int events with E1+E2 > 4 MeV
 0.05 bb0n-like events year-1 kg -1 with 2.8<E1+ E2<3.2 MeV
208Tl impurities inside the foils ~ 60 mBq/kg
Measured with (e-,2g), (e-,3g) events coming from the foil
~ 0.06 bb0n-like events year-1 kg -1 with 2.8<E1+ E2<3.2 MeV
Radon background suppressed by a factor 10 in Dec with a radon-free air purification system
Radon inside NEMO-3 detector
Measured with (e-,g,a) events from the gas or the foil
~ 1 bb0n-like events year-1 kg -1 with 2.8<E1+ E2<3.2 MeV
100Mo bb2n decay T1/2 = y
~ bb0n-like events year-1 kg -1 with 2.8<E1+E2<3.2 MeV

16. Limit on the effective mass of the Majorana neutrino
Phase 1 (Feb – Sept. 2004: 1.08 y of data) with radon bkg
90% CL)
100Mo
Previous limits: T1/2(bb0n) > y
Ejiri et al. (2001)
100Mo (6.914 kg)
T1/2(bb0n) > y
mn < 0.66 – 2.81 eV
[ ] MeV: e(bb0n) = 8 %
Expected bkg = 8.1 ± 1.3
Nobserved = 7 events
Nuclear Matrice Elements Ref: Simkovic (1999), Stoica (2001), Suhonen (1998,2003), Rodin (2005), Caurier (1996)
82Se
Previous limits: T1/2(bb0n) > y
Arnold et al. (1992)
82Se (0.932 kg)
T1/2(bb0n) > y
mn < 1.75 – 4.86 eV
[ ] MeV: e(bb0n) = 13 %
Expected bkg = 3.1 ± 0.6
Nobserved = 5 events
Cu+natTe+130Te
In agreement with only
Radon bkg expected

17. Limit on Majoron and on V+A (limits @ 90% CL)
100Mo: T1/2 (bb0nM) > y Se: T1/2 (bb0nM) > y
gM < (5.3 – 8.5) (best limit) gM < (0.7 – 1.6) 10-4
Simkovic (1999), Stoica (1999) Simkovic (1999), Stoica (2001)
Limit on V+A
100Mo: T1/2 (bb0n V+A) > y Se: T1/2 (bb0n V+A) > y
l < (1.5 – 2.0) l <
Tomoda (1991), Suhonen (1994) Tomoda (1991)

18. Free-Radon Purification System
in construction
Radon was the dominant
background for NEMO-3
Today: A(222Rn) in the LSM ~ 15 Bq/m3
Factor ~ 10 too high
May 2004 : Tent surrounding the detector
May 2004
August 2004 : Radon-free
SuperKamiokande-like
Air Factory
Expected activity:
A(222Rn) ~ 0.2 Bq/m3
150 m3/h
2 x 450 kg -40oC
Expected Purification Factor ~ 75
Laurent Simard for the NEMO-3 Collaboration WIN 05 Delphi June 2005

19. Radon-free air factory Activity: A(222Rn) < 1 mBq/m3 !!!
Starts running on October 2004 the 4th
In Laboratoire Souterrain de Modane
2 x 450 kg -50oC, 7 bars
Activity: A(222Rn) < 1 mBq/m3 !!!
Flux: 125 m3/h

21. After installation of radon-free air factory (active charcoal)
222Rn Activity between february 2003 and september 2004 ~ 0.95 Bq 40
Time (days) 17
now ~ 0.1 Bq (réduction by a factor ~ 10)
Only 0.7 evt/y of background for bb0n of 100Mo < Nbdf due to bb2n

22. NEMO-3 Expected sensitivity
Background
External Background: negligible
Internal Background: 208Tl : 60 Bq/kg for 100Mo
300 Bq/kg for 82Se
214Bi : < 300 Bq/kg
~ 0.1 count kg1 y 1 with 2.8<E1+E2<3.2 MeV
 100Mo T1/2 = y
~ 0.3 count kg1 y 1 with 2.8<E1+E2<3.2 MeV
in 2009 after 5 years of data
6914 g of 100Mo T1/2()  y (90% C.L.)
m < – 1.35 eV
932 g of 82Se T1/2()  y (90% C.L.)
m < – 1.72 eV
Nuclear Matrice Elements Ref: Simkovic (1999), Stoica (2001), Suhonen (1998,2003), Rodin (2005), Caurier (1996)

23. CONCLUSIONS ON NEMO3 NEMO-3 Detector running since 14 Feb. 2003
Expected performance of the detector has been reached !
2b2n preliminary results for 100Mo, 82Se, 96Zr, 116Cd and 150Nd
already more than b2n events collected
100Mo: in favour of Single State Dominance (SSD)
100Mo bb2n decay to excited state has been measured with ~ 4 s
Preliminary T1/2(bb0n) limit (1.08 years of data):
100Mo (4.10 kg.y) T1/2(bb0n) > y  mn < 0.7 – 2.8 eV
82Se (0.55 kg.y) T1/2(bb0n) > 1023 y  mn < 1.8 – 4.9 eV
Level of backgounds as excepted
Free radon purification system in operation in August 2004
Reduction of the radon level by a factor ~10
Expected sensitivity in 5 years after radon purification
100Mo: T1/2(bb0n) > y <mn> < 0.32 – 1.35 eV
82Se: T1/2(bb0n) > y <mn> < – 1.72 eV
Laurent Simard for the NEMO-3 Collaboration WIN 05 Delphi June 2005

24. The SUPERNEMO project
Idea : continue with a tracko-calo like detector with a mass of few 100 kg of 82Se (T 1/2 bb2n ~ 15 times greater than for 100Mo,
Q bb around 3 MeV also)
3 years R&D program
Laurent Simard for the NEMO-3 Collaboration WIN 05 Delphi June 2005

25. Internal contaminations in the source foils in 208Tl and 214Bi
From NEMO-3 to SuperNEMO
NEMO-3
SuperNEMO
7 kg 100Mo
T1/2(bb2n) = y
100 kg 82Se
T1/2(bb2n) = 1020 y
Mass of isotope
T1/2(bb0n) > y
<mn> < 0.3 – 1.3 eV
T1/2(bb0n) > y
<mn> < 40 – 110 meV
Sensitivity
Energy resolution
FWHM ~ 12% at 3 MeV
(dominated by calorimeter ~ 8%)
FWHM ~ 7% at 3 MeV
(dominated by source foil)
Efficiency
e(bb0n) = 8 %
poor energy resolution
e- backscattering on scintillator
e(bb0n) ~ 40 %
Internal contaminations
in the source foils in 208Tl and 214Bi
214Bi < 300 mBq/kg
208Tl < 20 mBq/kg
214Bi < 10 mBq/kg
208Tl < 2 mBq/kg
Background
bb2n ~ 2 cts / 7 kg / y
(208Tl, 214Bi) ~ 0.5 cts/ 7 kg /y
bb2n + (208Tl,214Bi)
≤ 1 cts/ 100 kg /y

26. SuperNEMO preliminary design Side view
Plane and Modular Geometry (~5 kg of enriched isotope/module)
1 Module: Source (40 mg/cm2) 4 x 3 m2
Tracking volume: drift wire chamber in Geiger mode, ~ 3000 cells
Calorimeter: scintillators + PMTs (~1000 PMTs)
20 modules: 100 kg of enriched isotope
~ channels for drift chamber
~ PMT if scint. block
~ PMT if scint. bars
4 m
1 m
5 m
Top view

27. Need of cavity of ~ 60m x 15m x15m
Water shield
1,5m
Need of cavity of ~ 60m x 15m x15m
Possible in Gran Sasso or in Modane if a new cavity

28. sources R&D GOAL : A(214Bi) < ~ 10 mBq/kg A(208Tl) < ~2 mBq/kg
not only enrich and purify sources, but also measure their radiopurity
2 mBq/kg of 1 kg of sources give 64 decays/year !!!
sensitivity in 208Tl of High Purity-Germanium detectors used for the measurement of NEMO3 sources : 60 mBq/kg

29. calorimetry R&D
Goal : reach FWHM less than 4% at 3 MeV (for NEMO-3 8%)
6% (source) (+) 4 % (calo) ~ 7 % (global)
Idea : stay with plastic scintillators (to keep time of flight) but improve resolution
collaboration CEN Bordeaux Gradignan-LAL-Kharkov-Dubna already promising results
In addition : some english groups working on inorganic scintillators
One option : reduce thickness of scintillator to collect more photons produced by scintillation and separate tagging of g from the energy measurement of the e-
optimisation of the shape of the scintillator (small bloc, long bar read by several PMTs…)
Need to improve also the performances of photomultiplier : scintillator adapted to PMTs, improve quantum efficiency
collaboration CEN Bordeaux Gradignan-Photonis

30. Other projects CUORE bolometer 130Te 741 kg of natural Tellurium, 10 y
b=10-2/(keV.kg.y)
R = 10 keV
T ½ (bb0n) > y
mee < eV
b=10-3/(keV.kg.y)
R = 5 keV
T ½ (bb0n) > y
mee < eV
GERDA
Phase I : 15kg.y b=10-1/(keV.kg.y)
T ½ (bb0n) > y
mee < eV
HP-diode 76Ge
Phase II : 100kg.y b=10-3/(keV.kg.y)
T ½ (bb0n) > y
mee < eV

31. MOON : tracking with scintillating fibres with 100Mo
Other projects
EXO : TPC with liquid 136Xe, tagging of the decay product by
bb0n (barium ion) with a laser
10 tons, they already have prototype of 200 kg of xenon (80% of 136Xe)
b=0.015 c/(keV.kg.y) T ½ (bb0n) > y mee < eV
MAJORANA : segmented
diodes of HP-Ge
500 kg of 86% 76Ge, 10 y
T ½ (bb0n) > y
mee < 0.007 eV
MOON : tracking with scintillating fibres with 100Mo

32. SuperNEMO is a large scale bb0n detector
Conclusions
If any bb0n signal seen in any isotope, it will HAVE to be observed by a tracko-calo detector « a la NEMO » to tag the 2 e- emitted in bb0n decay
NEMO-3 reached the expected performance and nominal background data taking will continue up to 2009
expected sensitivity: T1/2(bb0n) > with 7 kg of 100Mo
T1/2(bb0n) > with 1 kg of 82Se
NEMO technique can be extrapolated to 100 kg
R&D program in order to reach T1/2(bb0n) > y  <mn> < 40 – 110 meV
DE/E < 7% 3 MeV =  (DE/E sources)2 + (DE/E calorimeter)2
e(bb0n) ~ 40%
208Tl < 2 mBq/kg and 214Bi < 10 mBq/kg
SuperNEMO is a large scale bb0n detector
Need an international collaboration: France, Russia, UK, Tchec., Japan and USA !