0. Double beta decay experiments
F. Piquemal
Modane Underground Laboratory (CNRS/NI2P3 and CEA/Irfu)
Many thanks to : K. Zuber, S. Schoenert, K. Inoue, A. Giuliani, S. Elliot, M. Chen,
M. Nomachi, N. Ishihara. H.J. Kim, F. Danevich, L. Winslow
TPC Paris Decembre,

1. Double beta decay : physics case
Nature of neutrino Dirac or Majorana
Neutrino mass hierarchy
Right-handed current interaction
CP violation in leptonic sector
Search of Supersymetry and new particles

2. Double beta decay observables
(A,Z) (A,Z+2) + 2 e-
Mass vs Right-Handed Current mechanism
Angular distribution MM
RHC
Ee1 – Ee2 distribution
sum electron energy / Q
Decay to Excited States
(A,Z)  (A, Z+2) + 2 e- + 1,2 g
1 or 2 additonnal g-rays
Identification
of daugther nucleus :
Xe  Ba e-
F. Piquemal
TPC 2014 (APC Paris)

3. Isotope choice F. Piquemal TPC 2014 (APC Paris)
Dueck et al. Phys,. Rev. D (2011)
F. Piquemal
TPC 2014 (APC Paris)

4. Isotope enrichment Nucleus Existing method R&D 48Ca
R&D in KAERI (Korea) for
48Ca enrichment by laser
Nucleus
Existing method
R&D
48Ca
Laser separation, gazeous diffusion
76Ge
Centrifugation
82Se
96Zr
Laser separation
100Mo
116Cd
130Te
136Xe
150Nd
Centrifugation, Laser
R&D in Russia for
150Nd enrichment
by centrifugation
R&D in France for
150Nd enrichment
by laser
F. Piquemal
TPC 2014 (APC Paris)

5. Backgrounds Background origins  M . t WITH Background NBckg . DE (y)
e :efficiency, M: Mass, t: time, Nbckg: Background events, DE: energie resolution, A: isotope mass
Background origins
Natural radioactivity
Other sources of background:
Muons (underground labs)
g from ( (n,g) reactions , m bremstrahlung
Muon spallation products
a emitters from bulk or surface contaminations for calorimeters
bb(2n) if modest energy resolution
208Tl (2.6 MeV g )
214Bi (and radon)
208Tl (and thoron)
E (MeV)
40K, 60Co,…
Transistion energy Qbb
Different strategies are possible to minimize the background
F. Piquemal
TPC 2014 (APC Paris)

6. Next generation of experiments
Calorimeter
Tracker
Ge diode
76Ge
e, DE
GERDA
MAJORANA
Tracko-calo
82Se (150Nd,48Ca)
NBckg , isotopes
SuperNEMO
CUORE
LUCIFER
Lumineu
Amore
Bolometers
130Te,82Se,100Mo
e, DE
Pixellized CdZnTe
116Cd
e, NBckd
COBRA
Liquid Xe
136Xe
e,M,(Nbckd)
EXO
MTD
EXO-gas
NEXT
TPC
136Xe, 150Nd
e, NBckd
KamLAND-Zen
CANDLES
SNO+
Borexino
CdWO4
AMoRE
Scintillator
136Xe, ,48Ca,
150Nd, 100Mo
e, M
F. Piquemal
TPC 2014 (APC Paris)

7. Required background level
Goal of the next generation
In case of bb(0n) through light neutrino exchange
Isotope
mass
Required background level
in the ROI
~ 10 kg
100 – 1000 cts/yr/ton
(200 – 400kg 136Xe)
~ 100 kg
1 – 10 cts/yr/ton
~ 1000 kg
0.1 – 1 cts/yr/ton
|mee|
S T Petcov 2009 J. Phys.: Conf. Ser
10 kg: T1/2 > years kg: T1/2 > years :
Next generation will use ≥ 100 kg (started with Xe experiments)
Improvements of background level needed
F. Piquemal
TPC 2014 (APC Paris)

8. SuperNEMO Construction NEXT R&D EXO R&D MTD (DCBA) R&D COBRA R&D
Tracking experiments
SuperNEMO Construction
NEXT R&D
EXO R&D
MTD (DCBA) R&D
COBRA R&D
F. Piquemal
TPC 2014 (APC Paris)

9. NEMO3 Unique feature e- e-
Tracking detector: drift chambers (6180 Geiger cells)
t = 5 mm, z = 1 cm ( vertex )
Calorimeter (1940 plastic scintillators and PMTs)
Energy Resolution FWHM=8 % (3 MeV)
Identification e-,e+,
Very high efficiency for background rejection
Background Qbb [2.8 – 3.2 MeV] : cts/keV/kg/y
Multi-isotope (7 measured at the same time)
Running at Modane underground laboratory ( )
Unique feature
Measurement of all kinematic parameters:
individual energies and angular distribution E1 e-
event e-
E1+E2= 2088 keV
t= 0.22 ns
(vertex) = 2.1 mm E2
[2.8 – 3.2] MeV 18 observed events, ± 1.3 expected
100Mo T1/2 (bb0n) > y (90% C.L.)
<mn> < 0.31– 0.79 eV
Measurement of 7 isotopes bb(2n) half-lifes
Excited states, Majoron limits for bb(0n)

10. SuperNEMO 20 modules A module Located in LSM extension
Demonstrator module
20 Modules
Source : 82Se
7 kg
100 kg
Drift chambers for tracking
2 0000
40 000
Electron calorimeter
500
10 000
g veto (up and down)
100
2 000
T1/2 sensitivity y
(No background) y
<m> sensitivity
200 – 400 meV
40 – 100 meV
F. Piquemal
TPC 2014 (APC Paris)

11. SuperNEMO Objective: to reach the background level for 100 kg
to perform a no background experiment with 7 kg isotope of 82Se in 2 yr
Source
214Bi < 10 mBq/kg
(NEMO3 100 mBq/kg)
208Tl < 2 mBq/kg
(NEMO3 100 mBq/k)
Calorimeter
DE/E < 3 MeV
(NEMO3 8.6% at 3MeV)
Tracker
3.7 m long (NEMO3 2.7 m)
t = 5 mm, z = 1 cm
Radon < 0.15 mBq/m3
(NEMO3 5 mBq/m3)
Wiring robot
Global efficiency : 30 % (NEMO3 8%)

12. SuperNEMO Demonstrator status
Scintillators production and 8’’ Hamamatsu PMT’s in production
FE digitizer boards OK, control and trigger boards under development
Blocks, wall design and technical tests OK  construction in progress 1st LSM in 2014
Calorimeter
- Automated drift cells production ongoing with the wiring robot
- First 1 / 4 tracker C0 tested for radon emanation and cells propulation
- C0 commissioning at see-level and in 2014
Tracker
- 5.5 kg of 82Se , 4.5 kg already purified. Purchase of 1.5 kg in progress
- Source materials (glue, films,…) under HPGE and BiPO selection processes
- Calibration sources deployment system and LED survey system under test
Source
F. Piquemal
TPC 2014 (APC Paris)

13. SuperNEMO demonstrator module
Calorimeter
Source
Ultra low background detector
Modular detector with 3 main components :
Central source foil frame : 7 kg of isotope
Tracking : drift chambers
Calorimeter : 712 scintillators+ PMTs
Shielded by iron (300 tons) and water
Construction in progress
Installation and commissioning at Modane Underground Laboratory 2015 – 2016
Data taking 2016
tracker
No background expected for 2 years of data. 7 kg 82Se T1/2 > y <mn> < 0.16 – 0.44 eV

14. COBRA Cobra Use large amount of CdZnTe Semiconductor Detectors
Source = detector
• Focus on 116Cd
Semiconductor (Good energy resolution, clean)
Room temperature
Modular design (Coincidences)
Tracking/Pixelisation („Solid state TPC“)
K. Zuber, Phys. Lett. B 519,1 (2001)
F. Piquemal
TPC 2014 (APC Paris)

15. COBRA
Cobra
Objective : Massive background reduction by particle identification
Bi-214 =
Time coincidence of both
55 μm pixel real event
alpha
electron
alpha
electron
Real event!
Current spectrum (black), kg*days
Background at 2813 keV about 1 ct/keV/kg/yr
Currently ongoing upgrade:
64 detectors (in hand) 32 running at LNGS
Pulse shape information
rejection of surface events
116Cd peak region
F. Piquemal
TPC 2014 (APC Paris)

16. MTD (Magnetic Tracking Detector: temporary name) following of DCBA
Magnetic Tracking Detector (DCBA)
MTD (Magnetic Tracking Detector: temporary name) following of DCBA
Chamber cell : the same as DCBA-T3, Source plate: 80 m2/module
Thickness: 40 mg/cm2, Source weight: 32 kg/module
Expected Energy Resolution 3.4% at Qbb for 150Nd
Multi-isotope 150Nd, 100Mo, 82Se
Several modules to reach <mn> 50 meV
F. Piquemal
TPC 2014 (APC Paris)

17. Calorimetric experiments
GERDA II In progress
CUORE In progress
KamLAND-Zen In progress
CANDLES Data taking
SNO In preparation
MAJORANA Completion of R&D
LUCIFER R&D
ZnMoO R&D
Amore R&D
CdWO R&D
F. Piquemal
TPC 2014 (APC Paris)

18. Ge diodes
L. Winslow Neutrino 2014
F. Piquemal
TPC 2014 (APC Paris)

19. GERDA II : Ge diodes Ge detectors in liquid nitrogen installed @ LNGS
Phase I: kg of enriched detectors
Background level after Pulse shape discrimination
0.01 cts/(keV.kg.yr).
Exposure 21.6 kg.yr
GERDA: T1/2 > yr (90%CL)
GERDA+ IGEX. HM T1/2 > yr
<mn> < 0.2 – 0.4 eV

20. GERDA II : Ge diodes Integration of the elements of GERDA phase II
40 kg of enriched Ge detectors
- First deployment of the liquid argon scintillation readout.
- First pilot string will be deployed together with the LAr scintillation read out.
- Deployment of the full array of enriched Ge detectors early next year.
Phase II is designed to reach T1/2 > 1026 years.
F. Piquemal
TPC 2014 (APC Paris)

21. Majorana : Ge diodes
Improvement of the radiopurity of the materials, Pulse shape
Cryostat 1 (3 strings enrGe & 4 strings natGe) (Fall 2013)
Cryostat 2 (up to 7 strings enrGe) (Fall 2014)
Final design of demonstrator 30 kg of 76Ge and 10 kg of natGe
Differs from Steve’s version
F. Piquemal
TPC 2014 (APC Paris)

22. KamLAND-ZEN (Kamioka)
Purification of liquid scintillator to remove 110mAg
Improvement of spallation cut
Improvement of fiducial volume selection
F. Piquemal
TPC 2014 (APC Paris)

23. KamLAND-ZEN prospectives
F. Piquemal
TPC 2014 (APC Paris)

24. CUORE: bolometers 741 kg of TeO2 bolometers (206 kg of 130Te) @ LNGS
CUORE-0 has validated the energy resolution
And background results are encouraging
All the towers are assembled
Cryostat cooled down to 6 mK with 470 kg of Cu
Presently, cooling with 8 bolometers for test
F. Piquemal
TPC 2014 (APC Paris)

25. CANDLES III 96 CaF2: 305kg (57 g of 48Ca) + liquid scintillator
Measurement started in June 2011.
CANDLES III
@ Kamioka
Cooling system(~0℃) (october 2014)
Coils to compensate magnetic filed
Improvement of energy resolution 4% Qbb
Enrichment of 48Ca (2%)
F. Piquemal
TPC 2014 (APC Paris)

26. SNO+
NatTe dissolved in liquid scintillator (0.3% corresponding to 800 kg of 130Te
5 years of data
F. Piquemal
TPC 2014 (APC Paris)

27. Scintillating bolometers
Example of b/a rejection with a 5 g detector
Light/Heat [keV/keV]
Shape parameter
Heat energy [keV]
Heat energy [keV]
F. Piquemal
TPC 2014 (APC Paris)

28. Bolometric Light Detector
LUCIFER
Scintillating bolometers to recognize the -induced background thanks to
the readout of the scintillation light
Zn82Se crystal
(Ø=45mm, h= 55 mm)
W=483 g
Reflecting Foil
PTFE supports
Bolometric Light Detector
Ge crystal
Array of 36÷44 enriched (95%) Zn82Se crystals.
Expected background in the ROI (2995 keV) is  3 c/keV/kg/y
Energy resolution 10 keV FWHM
F. Piquemal
TPC 2014 (APC Paris)

29. Calibration aboveground spectrum
LUMINEU
Calibration aboveground spectrum
Two enriched crystals of 60 g each obtained
Excellent performance aboveground (CSNSM, Orsay)
No difference with respect to natural crystals
nderground tests of a few large mass enriched crystals (foreseen within June 2015)
If radiopurity is confirmed:
Start-up of LUCINEU project (LUCIFER+LUMINEU)
Systematic production of  40 crystals containing  7 kg of 100Mo (MoU INFN+IN2P3+ITEP)
Cool down of this 40 crystal array during 2016 in LNGS and/or LSM (depending on cryostat availability)

30. Background (yr/keV/kg)
AMORE
(Advanced Mo-based Rare process Experiment)
40Ca100MoO4 bolometers
15 keV FWHM, Eff = 0.8
AMoRE Pilot, 2015
5 bolometers de CaMoO  1,5 kg
　Stage
Start (run, yr)
Background (yr/keV/kg)
Sensitivity
limT1/2 (yr)
m (eV)
AMoRE pilot
Jan (1)
0.01
~1.5x1024
<0.3 – 0.9
AMoRE 10
Sep (3)
0.002
~2x1025
AMoRE 200
Jan (5)
0.0002
~41026
F. Piquemal
TPC 2014 (APC Paris)

31. Studied isotopes Nat(48)Ca 116Cd 76Ge Nat(150)Nd 82Se 136Xe 48Ca 100Mo
GERDA
MAJORANA
KamLAND-Zen
EXO - NEXO
NEXT
Lumineu
AMoRE
SuperNEMO
LUCIFER
COBRA
CdWO4
CUORE
SNO+
Borexino
CANDLES
Nat(48)Ca
116Cd
76Ge
Nat(150)Nd
82Se
48Ca
150Nd
CANDLES
SuperNEMO
AMoRE
SNO+
MTD
Borexino
A dream ?
136Xe
100Mo
130Te
F. Piquemal
TPC 2014 (APC Paris)

32. Half-life to reach for <mn> = 50 meV
Experimental limit (90%CL)
GERDA
EXO-200
KamLAND-Zen
CUORE
NEMO3
NEMO3
Solotvina
CANDLES
NEMO3

33. Summary
Present experiments at the level of T1/2 > 1024 – 1025 years
<mn> < 0.15 – 0.5 eV
Several experiments at 100 kg are needed to understand backgrounds and
determine the best isotope and technique for higher mass
Sensitivity : T1/2 > 1026 – 1027 years
<mn> < 0.05 – 0.1 eV
Starting to test of the inverted hierarchy scenario
: starting of GERDA II, Majorana, SuperNEMO, SNO+, CUORE,
scintilating bolometers
Still a long way to reduce the background.
In case of signal a tracking experiment will be needed to confirm it