SNOW 2006, StockholmNEMO 3 and SuperNEMO experiments Vladimir Vasiliev, UCL 2-6 May ’06, Stockholm...
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Transcript of SNOW 2006, StockholmNEMO 3 and SuperNEMO experiments Vladimir Vasiliev, UCL 2-6 May ’06, Stockholm...
SNOW 2006, StockholmNEMO 3 and SuperNEMO experiments
Vladimir Vasiliev,UCL2-6 May ’06, Stockholm
on behalf of NEMO and SuperNEMO collaborations
NEMO collaboration: IReS, Strasbourg, France; LAL, Orsay, France; INEEL, Idaho Falls, USA; ITEP, Moscow, Russia; CENBG, Bordeaux-Gradignan; JINR, Dubna, Russia; IEAP, Prague, Czech Republic; UCL, London, UK; LPC, Caen, France; Saga Universityt, Japan; LSCE, Gif-sur-Yvette, France; Jyvaskyla University, Finland; MHC, South Hadley, USA; Charles University, Prague, Czech Republic; Manchester University, UK.
SuperNEMO collaboration: CENBG Bordeaux-Gradignan; IReS, Strasbourg, France; LAL, Orsay, France; LPC, Caen, France; LSCE Gif-Sur-Yvette, France; Jyvaskula Uiversity, Finland; Saga University, Japan; Osaka University, Japan; Fes University, Marocco; INR RAS, Moscow, Russia; ITEP, Moscow, Russia; JINR, Dubna, Russia; RRC Kurchatov Institute, Moscow, Russia; Charles University, Prague, Czech Republic; Technical University, Prague, Czech Republic; Manchester University, UK; UCL, London, UK; ISMA, Kharkov, Ukraine; INEEL Idaho Falls, USA; Mount Holyoke College, USA; University of Texas, USA; IFIC, Valencia, Spain; Canfranc laboratory, Zaragosa, Spain;
NEMO 3 and SuperNEMO experiments
SNOW 2006, StockholmNEMO 3 and SuperNEMO experiments
Neutrinoless decay
Experimental signature:
a) 2 electronsb) E+ EQ
NEMO 3. Tracking experiment a) and b). Better signature, control and suppression of background. But worse resolution.
Ultimate background – decay tail.
SNOW 2006, StockholmNEMO 3 and SuperNEMO experiments
3 m
4 mB (25 G)
20 sectors
NEMO-3 detectorFrejus underground laboratory 4800 m.w.e.
Source: 10 kg of isotopes, foil ~ 50mg/cm2
Tracking detector: drift wire chamber operating in Geiger mode (6180 cells) Gas: He + 4% ethyl alcohol + 1% Ar + 0.1% H2O
xy=0,6 cm; z=1,3 cm;
Calorimeter: 1940 plastic scintillators coupled to low radioactivity PMTsFWHM=14% (5”); 17% (3”) @ 1MeV
Time resolution = 0.25 ns @ 1MeV detection efficiency ≈ 50 %
Magnetic field: 25 Gauss (3% e+/e- confusion @ 1 MeV)
Gamma shield: Iron (e = 18 cm)Neutron shield: 30 cm water + boron (ext. wall); 40 cm wood (top and bottom)
Able to identify e, e, and
SNOW 2006, StockholmNEMO 3 and SuperNEMO experiments
isotope foils
scintillators
PMTs
Calibration tube
Cathodic rings Wire chamber
SNOW 2006, StockholmNEMO 3 and SuperNEMO experiments
100Mo 6.914 kg Q= 3034 keV
82Se 0.932 kg Q= 2995 keV
116Cd 405 g Q= 2805 keV
96Zr 9.4 g Q= 3350 keV
150Nd 37.0 g Q= 3367 keV
Cu 621 g
48Ca 7.0 g Q= 4272 keV
natTe 491 g
130Te 454 g Q= 2529 keV
measurement
Background measurement
search
isotopes in NEMO-3
SNOW 2006, StockholmNEMO 3 and SuperNEMO experiments
Background model External background
Detector radioactivity (PMT, iron, flux from lab). Measured by Compton scattering in the foil.
Radon in tracking chamber 214Bi pollution of wires and foil surfaces. Measured
by delayed 214Po -decay. Source foil
Internal radioactivity. e and eevents from foil. decay
Cu foil
SNOW 2006, StockholmNEMO 3 and SuperNEMO experiments
Radon free air facility
compressor9-10 bar
buffer
dryer
adsorption unit @ -50°C
cooler & heater
15 Bq/m3
15 mBq/m3
In the tent around NEMO 3 Rn = 150 mBq/m3 In the tracker Rn = 4.5 mBq/m3 does not depend any more from Rn level in the tent.
2 sets of dataPhase-I, before 4/10/04, Rn ≈ 22.2 mBq/m3, Phase-II, Rn=4.5 mBq/m3
SNOW 2006, StockholmNEMO 3 and SuperNEMO experiments
results for 100Mo
T1/2 = 7.11 0.02 (stat) 0.54 (syst) 1018 yPhys Rev Lett 95, 182302 (2005)
SSD model confirmed
HSD, higher levels contribute to the decay
SSD, 1 level dominates in the decay (Abad et al., 1984, Ann. Fis. A 80, 9)
100Mo
0
100Tc
1
Decay to the excited 0+ state of 100RuT1/2 = 5.7 1.3 (stat) 0.8 (syst) 1020 y
To be published soon
Phase I + II ( 587d)Use MC Limit approach: shape information, different background level for PI and PIIE1+E2>2 MeV12952 evs MC = 12928 ± 70
TT1/21/2 > 5.6∙10 > 5.6∙102323 y, 90% CL y, 90% CL
Window method [2.78-3.20] MeV, (690d)Window method [2.78-3.20] MeV, (690d)14 evs MC = 13.4 =8.2 %
TT1/21/2 > 5.8∙10 > 5.8∙102323 y, 90% CL y, 90% CL
Simkovic, J. Phys. G, 27, 2233, 2001
Single electron spectrum different between SSD and HSD
Esingle (keV)
SSD simulation
SNOW 2006, StockholmNEMO 3 and SuperNEMO experiments
results for 82Se
T1/2 = 9.6 0.3 (stat) 1.0 (syst) 1019 yPhys Rev Lett 95, 182302 (2005)
Phase I + II ( 587d)Use MC Limit approach
E1+E2>2 MeV238 evs MC = 240.5 ± 7
TT1/21/2 > 2.7∙10 > 2.7∙102323 y, 90% CL y, 90% CL
Window method [2.62-3.20] MeV, (690d)Window method [2.62-3.20] MeV, (690d)7 evs MC = 6.4 =14.4 %
T > 2.1∙10T > 2.1∙102323 y, 90% CL y, 90% CL
SNOW 2006, StockholmNEMO 3 and SuperNEMO experiments
decay for other isotopes
116Cd, T1/2=(2.8±0.1(stat)±0.3(syst))∙1019 y
150Nd , T1/2=(9.7±0.7(stat) ±1.0(syst))∙1018y
96Zr, T1/2 =(2.0±0.3(stat)±0.2(syst))∙1019y
48Ca, T1/2=(5.3±0.9(stat)±0.5(syst))∙1019 y
Very preliminary results, to be crosschecked and published soon
SNOW 2006, StockholmNEMO 3 and SuperNEMO experiments
Exotic processes search
V+A current in electroweak lagrangian Neutrino coupled axions (majorons)
V+A * n=1 ** n=2 ** n=3 ** n=7 **
Mo >3.2∙1023
<1.8∙10-6 [1]
>2.7∙1022
g<(0.4-1.8)∙10-4 [3]
>1.7∙1022 >1.0∙1022 >7∙1019
Se >1.2∙1023
2.8∙10-6 [2]
>1.5∙1022
g<(0.7-1.9)∙10-4 [3]
>6.0∙1021 >3.1∙1021 >5.0∙1020
* new PI+PII data** R.Arnold et al. Nucl. Phys. A765 (2006) 483NME Calculations:[1] J. Suhonen, Nucl. Phys. A 700 (2002) 649[2] M. Aunola and J. Suhonen, Nucl. Phys. A 463 (1998) 207[3] F. Simkovic et al., Phys. Rev. C 60 (1999) 055502; S.Stoica and H. Klapdor-Kleingrothaus, Nucl. Phys. A 694 (2001) 269; O. Civatarese and J. Suhonen, Nucl. Phys. A 729 (2003) 867
SNOW 2006, StockholmNEMO 3 and SuperNEMO experiments
SuperNEMO project
extension of NEMO 3 technique 100 kg of isotopes, thin source between tracking
volumes, surrounded by calorimeter. sensitivity 1-2∙1026 y, 40-70 meV main improvements needed:
energy resolution (8% FWHM @ 1MeV ≡ 4% @ 3MeV)
detection efficiency (factor 2) source radio purity (factor 10) background rejection methods
SNOW 2006, StockholmNEMO 3 and SuperNEMO experiments
SuperNEMO milestones
2006-8: Design studyCalorimeter
Tracker
Source
Site selection (Frejus, Gran Sasso, Canfranc, Bulby)
Approved and funded R&D program in UK and France. Spain, Russian and Japan groups applied for funding.
end 2008: Full Proposal
2009 – 2011: Production
2010-2011: Start taking data
2015: planned sensitivity ~0.04 eV
SNOW 2006, StockholmNEMO 3 and SuperNEMO experiments
Modular design
Top view Side view
5 m
1 m 4 m
source
tracker
calorimeter
SNOW 2006, StockholmNEMO 3 and SuperNEMO experiments
Alternative design (bar scintillator)
Double sided readout
SNOW 2006, StockholmNEMO 3 and SuperNEMO experiments
Calorimeter R&D so far
7-8% FWHM @ 1MeV for small scintillator 5x5x2 cm
9% FWHM @ 1 MeV for 15x15x2 cm … but because of light guide!
11-13% FWHM @ 1 MeV for 200 cm bar scintillator.
Attenuation length 150 cm! looking for better plastic.
SNOW 2006, StockholmNEMO 3 and SuperNEMO experiments
Wiring robot
The challenge:from 6,000 to~60,000+ cells
Wires must be strung terminated crimped
This can not be done manually (~10 min/wire)
Complications Copper pick-ups Must be cost effective Solder can not be used (radiopurity)
SNOW 2006, StockholmNEMO 3 and SuperNEMO experiments
BiPo device, ultra low purity msr.
Tracking (wire chamber)
Shield radon, neutron,
Source foil (40 mg/cm2)
Scintillator + PMT
2 modules 23 m2 → 12 m2
Background < 1 event / month
(300 ns)
232Th
212Bi(60.5 mn)
208Tl(3.1 mn)
212Po
208Pb(stable)36
%
(164 s)
238U
214Bi(19.9 mn)
210Tl(1.3 mn)
214Po
210Pb22.3 y0.
021%
Bi-Po Process
WHY? spectroscopy doesnt sensitive to purity level required ~10 Bq/kg
delay
e
Q(214Bi)=3.2 MeQ (212Bi) = 2.2 MeV
e
e prompt
T1/2 ~ 300 ns Edeposited ~ 1 MeV
Delay
SNOW 2006, StockholmNEMO 3 and SuperNEMO experiments
Isotope choice
Detector allows to hold any isotope. Choice depends on: - enrichment possibilities. Obligatory!- Q value (phase space factor, background)- life-time
82Se good candidate 100 kg per 2-3 y enrichment rate possible in Russia Q
= 2995 keV. Concern about 214Bi and 208Tl only. test 2kg sample produced. Under purification now
150Nd even better! SILVA group (SACLAY, France) was contacted. 150Nd enrichment is possible! Q
= 3367 keV. Concern about 208Tl only Large phasespace. 2tale only 1.6 bigger then for 82Se NME & G much better then for 82Se
SNOW 2006, StockholmNEMO 3 and SuperNEMO experiments
Conclusion
NEMO 3 is continuing to take data no signal so far.100Mo: T1/2>5.8∙1023 y; m<0.6-1.0 eV*
82Se: T1/2>2.1∙1023 y; m<1.2-2.5 eV*
*F. Simkovic et al., Phys. Rev. C 60 (1999) 055502; S.Stoica and H. Klapdor-Kleingrothaus, Nucl. Phys. A 694 (2001) 269; O. Civatarese and J. Suhonen, Nucl. Phys. A 729 (2003) 867 a number of results to be published soon SuperNEMO R&D is in progress. 3 year program
funded in UK and France.
WE ARE IN THE MIDDLE OF THE ROAD
EXIT
THAT COULD LEAD BEYOND SM
thank you for your attention!