NEMO-3 Detector Preliminary results • Performance of the detector • analysis for 100 Mo, 82 Se and 150 Nd Background study for research ( 208 Tl and Radon) Future of NEMO NEMO Experiment NEMO Experiment Neutrino Ettore Majorana Observatory Neutrino Ettore Majorana Observatory Journées Neutrinos 27-28 novembre 2003 LPNHE-Paris ier Sarazin for NEMO Collaboration
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NEMO-3 Detector Preliminary results Performance of the detector
Journées Neutrinos 27-28 novembre 2003 LPNHE-Paris. NEMO Experiment Neutrino Ettore Majorana Observatory. NEMO-3 Detector Preliminary results Performance of the detector 2b2n analysis for 100 Mo, 82 Se and 150 Nd Background study for 2b0n research ( 208 Tl and Radon) - PowerPoint PPT Presentation
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DDouble bouble beeta ta (0(0) ) decay : decay : Physics beyond the standard modelPhysics beyond the standard model
(0) : 2n 2p+2e- L = 2 Process Majorana Neutrino and effective mass
<m>
Right-handed current in weak interaction
Majoron emission
SUSY particle exchange
W
Wn
n
p
p
e
e
M
eR
eL
(Q ~ MeV)
( )T0
2/1
h
h
1 sector of NEMO3
Sources: 20 m2, total mass ~ 10 kg, thickness ~ 60 mm Tracking detector (6180 Geiger cells in He+alcohol): Vertex t = 5 mm, z = 1 cm Calorimeter (1940 plastic scintillators + PMTs low radioactivity) E/E = 3% at 3 MeV and neutron shield: Iron shield (18 cm) + water shield + wood shield + parafin magnetic field B=25 G all materials low radioactivity (total activity in 208Tl and 214Bi 300 Bq)
Located in Modane Underground LaboratoryLocated in Modane Underground LaboratoryNEMONEMO--3 3 DetectorDetector
isotope foils
scintillators
PMTs
Calibration tube
Cathodic rings Wire chamber
AUGUST 2001
June 2002 : tests runs
FFebruary 2003 :ebruary 2003 : bbeginning of data takingeginning of data taking
coil
Iron shield
Water tank
wood
Sources preparationSources preparation
Bkg
Sources thicknessmg/cm2)
Q= 3034 keV Q= 2995 keV
82Se (0.93 kg)100Mo (6.9 kg)
Sources in NEMO-3 detectorSources in NEMO-3 detector
Expected backgroundExpected background and sensitivity and sensitivity
Neutron and High-Energy gamma BackgroundNeutron and High-Energy gamma Background
Only 1 -like event > 4 MeV detected after 160 days of data tacking ! (14 Feb. 2003 – 30 Sep. 2003)
Run 2058 event 34596626 March 2003
130Te source (sector 19)
E1+E2 = 4448 keV
look for ee events > 4 MeV coming from the foil
Two different measurements of radon in the NEMO-3 gas:• Radon detector:
sensitivity: 1 count/day for 1 mBq/m3
Radon measurement 20 mBq/m3
• (1e + 1 ) channel in the NEMO-3 data:
Able to measure Radon every half day
Radon measurement 30 mBq/m3
~ a few 0-likeevents due to radon, expected in 1 year
!!! TOO HIGH !!!
A free Radon Tent surrounding the NEMO-3 detector in construction:• February 2004: 200 kg Charcoal Factor ~ 8 for Radon purification• Spring 2004: Full Radon purification system
Factor ~ 100
222Rn
218Po
214Pb
214Bi
214Po
210Pb
Radon in NEMO-3Radon in NEMO-3
s
E1+E2= 2880 keV
Run 2220, event 136.604, May 11th 2003
a a -like event due to Radon from the gas-like event due to Radon from the gas
track(delay = 70 s)214Po 210Pb
214Bi 214Po decay IN THE GAS
Fall 2003 : Tent surrounding the detectorA(222Rn) ~ Bq/m3
Today : A(222Rn) in the LSM ~10 Bq/m3
Spring 2004 : Radon-free Gas FacoryA(222Rn) ~ 0.2 Bq/m3
150 m3/h
Free-Radon Purification SystemFree-Radon Purification System
Sensitivity of NEMO3 to measure sources of backgroundSensitivity of NEMO3 to measure sources of background
Design NEMO3 for 10 kg: 208 Tl in source foils < 0.02 mBq/kg 214 Bi in source foils < 0.3 mBq/kg neutron flux < 10-8 n cm-2 s-1
Sensitivity NEMO3 after 2 years of data :
208 Tl in source foils < 2 Bq/kg channel e ’s (E= 2.6 MeV) 212 Bi 212 Po e (300 ns)
214 Bi in source foils < 2 Bq/kg measured by channel e ( ( 214 Bi 214 Po 210 Pb; T1/2 = 164 s )
neutrons < 10-9 n cm-2 s-1
measured by e- crossing > 4 MeV
Sensitivity to 100 kg of isotopes
Future for a NEMO Detector
Tracking-Calorimeter Technique
NEMO-3
NEMO-3
NEMO-3
QD
IH
QD
QD
IH
IH
Expected values of Expected values of mm from neutrinos oscillations parameters from neutrinos oscillations parameters
Pascoli and Petcov, hep-ph/0310003(best fit atm + sol )
Quasi-Degenerate (QD):
m > 0.6 eV
Inverted Hierarchie (IH):
0.015 eV < m < 0.6 eV
Normal Hierarchie (NH):
m < 5. 10-3 eV~
~
~~
Next Generation of NEMO detector« detect » 1 gold event/year
with m ~ 20 meV
Number of event detected / year:
ln2 . N . . MA . T1/2 (y)0
N / year N : AvogadroA : atomic massM : mass (g) of enrich. Isotope: detection efficiency
Future of NEMOFuture of NEMO
Real measurement with 1 GOLD EVENT / YEAR
• M = k 100 kg of 100Mo or 82Se• = 0.5• Background = 0.1 event / year• 1 Gold event detected / year
0T1/2 2 k 1026 yearsm = 20 – 60 meV
Goal of a next NEMO detector:
3-4-5 December 2003: 1st meeting for Future of NEMOStart working groups to prepare a design proposal for a future NEMO detector
Advantage of a Calo-Tracking approach:• Can measure several isotopes• Tag and measure all backgounds : zero background experiment• May detect « Gold events »
Start with realistic 100 kg isotope module…could be extended to 1 ton with several modules)
Main challenges:• Energy resolution• Efficiency• Sources (enrichment, purification)
Future of NEMOFuture of NEMO
ENERGY RESOLUTION IS ONE OF THE MAIN CHALLENGEENERGY RESOLUTION IS ONE OF THE MAIN CHALLENGEGoal: < 0.1 event/year in the energy window
FWHM ( ray at 3 MeV) 350 keV
one event/year expected in the energy windowNEMO-3 (7 kg):
2 ( ray) = 2 (Calorimeter) + 2 (dE/dX in foil) + 2 (dE/dX in tracking)
CALORIMETER: separate e/ measurement to improve e energy resolution(NEMO-3 ~ 15% at 1 MeV) electron: Silicon (Li) detector (~ 5 mm, noise ~ 20-30 keV at normal To)
Very good thin scintillator (~ 2 cm) gamma: thicker scintillators (100% efficiency instead of 50%)
SOURCES: Decrease the energy losses in the foil (NEMO-3 ~ 50-80 g/cm2, 60 m: <E> ~150 keV)
Active sources (ex: 2 foils 20 m + counters) internal Background rejection
TRACKING: Similar Geiger drift wire chamber TPC in He (Japan group)
e
208Tl internal bkg
ILIAS European funding ILIAS European funding for for research research
JRA1: low bkg. techn. for Deep Underground Laboratories• Links LSM and Boulby• Develop. Ultra Low Bkg. Facility: Big effort on Germanium• Radon factory
NEMO people involved in ILIAS (5 years)
JRA2: R&D for next detectors• R&D for calorimeter (silicon, scintillators…)• 82Se 2 kg production, purification and source making (2004-2005)• 150Nd enrichment study
N4: next generation of detectors• NEMO-Next working groups and Proposal
300 kEuros
300 kEuros
60 kEuros
IN2P3(5 years)
NOUVEAUX COLLABORATEURS
SONT LES BIENVENUS
New members already interested: USA (Texas University), UK (UCL), Japan (KEK)
CONCLUSIONSCONCLUSIONS
NEMO-3 Detector running since 14 Feb. 2003 Data tacking efficiency ~75%
Performance of the detector has been reached !
preliminary results for 100Mo, 82Se and 150Nd already more than 75.000 events collected
Background study for search:• 208Tl (e N channel) : good agreement with HPGe measurements• Neutrons and High-energy : only 1 -like event > 4 MeV !• Radon: 20-30 mBq/m3 inside the detector a few -like events/year expected Too high !
Free radon purification system under constructionRadon/8 in Feb. 2004Radon/50 in Spring 2004
Future of NEMO: First meeting 3-5 december 2003 start working groups to prepare a design proposal for a next detector
Goal (dream ?) for Next NEMO:be able to « detect » 1 gold event/year with m ~ 20 meV