Probing neutrino mass with SuperNEMO Ruben Saakyan Ulisse at LSM Workshop 30 June 2008

Probing neutrino mass withSuperNEMO

Ruben Saakyan

Ulisse at LSM Workshop

30 June 2008

30-Jun-2008 R. Saakyan: Ulisse at LSM Workshop. 2

Outline

• The Concept

• The Detector

• Physics reach

• Status of design study

• Schedule

• Summary


Neutrinoless double beta decay ()

L = 2!

1 20 0 0 21/ 2 0(0 0 ) ( , )T G E Z M

Lepton number violation parameter

can be due to , V+A, Majoron, SUSY, H-- or a combination of them!

Need detectors which can probe different mechanisms (and different isotopes)

m


T0

2/1 > . . A

M . t

NBkg . Eln2 . N

kC.L.

(y)

SuperNEMO experimental technique

M: masse (g) : efficiencyKC.L.: Confidence levelN: Avogadro numbert: time (y)NBckg: Background events (keV-1.g-1.y-1)E: energy resolution (keV)

Focus on lowering Nbkg and open-minded search for any lepton violating process

Calorimetry + Tracking

• Build on NEMO3 experience • Reconstruct two electrons in the final state (E1+E2 = Q)• Measure several final state observables

• Individual electron energies• Electron trajectories and vertices • time of flight • Angular distribution between electrons

• Background rejection through particle ID: e-, e+, , • Sources separated from detector can measure different isotopes


From NEMO-3 to SuperNEMO

7 kg 100-200 kg isotope mass M

18 % ~ 30 %

isotope 100Mo

82Se or/and 150Nd

T1/2 () > ln 2 M Tobs

N90

NA

A

NEMO-3 SuperNEMO

internal contaminations 208Tl and 214Bi in the foil

208Tl: < 20 Bq/kg214Bi: < 300 Bq/kg

208Tl Bq/kg

if 82Se: 214Bi 10 Bq/kg

T1/2() > 2 x 1024 y<m> < 0.3 – 0.9 eV

T1/2() > (1-2) x 1026 y<m> < 0.04 - 0.11 eV

energy resolution (FWHM) 8% @ 3MeV 4% @ 3 MeV

efficiency


USAMHCINL

U Texas

JapanU Saga

KEKU Osaka

FranceCEN Bordeaux

IReS StrasbourgLAL ORSAY

LPC CaenLSCE Gif/Yvette

UKUCL

U ManchesterImperial College

FinlandU Jyvaskula

RussiaJINR DubnaITEP Mosow

Kurchatov Institute

UkraineINR Kiev

ISMA Kharkov

Czech RepublicCharles U PrahaIEAP Praha

MaroccoFes U

Slovakia(U. Bratislava)

~ 90 physicists, 12 countries, 27 laboratories

SpainU Valencia

U SaragossaU Barcelona

SuperNEMO Collaboration

PolandU Warsaw


SuperNEMO preliminary design

Planar geometry. 20 modules for 100+ kg

Top view Side view

Source (40 mg/cm2) 12m2, tracking volume (~2k Geiger channels). calorimeter (600 channels)

5 m

1 m

4 m

Total: ~ 40 Geiger channels for tracking ~ 12k PMTs (3k if scintillator bars design)

Single model (baseline design)


Single sub-module with ~5-7 kg of isotope

~20 sub-modules for 100+ kg of isotopesurrounded by water shielding


1,5m

1,5

m

4,1

m

7,7

5m

2,4m

1m 1,5

m

J.FORGET SuperNEMO general design june 2008


100m

10m 12m

Hestorage

15m

Radonless air and gazmixtures production

ISO6workshop

Heavy work surface24,5

m

62m

17,5

m

46m


Choice of Isotope

Criteria of choice:

- High Q value- Phase space G

- half-life- natural abundance- enrichment possibilities

• purification of 4kg of 82Se underway (INL, US)• enrichment of 150Nd possible

82Se obtained by centrifugationImpossible for 150Nd, only laserenrichment


SuperNEMO simulations

• Full detector simulation– Event generator GENBB ( + radioactivity)– Geant 4– Reconstruction

• Tracks reconstructed from tracker hits and fitted

– Cellular automation for track patterns– Kalman filter for fitting

• Even vertex found in the foil

• Track matched with calorimeter hits

• Charge sign measured from curvature

• Draws heavily from NEMO3 experience

Overall efficiency ~30% (conservative scenario: B-field on, module width 1m, reject “double hits” etc..)

SNOVA


SuperNEMO simulations and physics reach

Se82 Nd150

“Con

serv

ativ

e” s

cena

rio

82Se:T1/2() =(1-2) 1026 yr depending on final mass, background and efficiency<m> 0.06 – 0.1 eV (includes uncertainty in T1/2) – MEDEX’07 NME150Nd:T1/2() =5 1025 yr <m> 0.045 eV (but deformation not taken into account)

Sensitivity


2006 – 2009

• Approved in UK, France and Spain. Smaller but vital contributions from US, Russia, Czech Republic, Japan.

• Main tasks and deliverables– R&D on critical components

• Calorimeter energy resolution of 4% (FWHM) at 3 MeV• Optimisation of tracking detector and construction

(robot)• Better background rejection (e.g. extra veto counters)• Ultra-pure source production and purity control • Simulations and geometry optimisation.

– Technical Design report in 2010– Experimental site selection (Frejus, Canfranc, Gran Sasso,

Boulby)

SuperNEMO Design Study


Calorimeter R&D

• Energy resolution is a combination of energy losses in foil and calorimeter E/E

• Goal: 7-8%/√E 4% at 3 MeV (82Se Q)

• Studies:– Material: plastic (PST, PVT) or liquid – Geometry and shape (blocks, bars)– Size– Reflective coating– PMT

• High QE• Ultra-low background

Factor of 2 compared to NEMO3!


Calorimeter R&D.

scintillator

Hamamatsu high-QE

PMT

207Bi

E/E = 6.5% E/E = 6.5% at 1 MeVat 1 MeV

3.8% at 3 MeV3.8% at 3 MeV

Scint. Block in

dark box

90Sr (370 MBq) e- beam

& trigger

DAQ


Scint Dimensions

(solid)

FWHM @ 1 MeV

PMT Size and Make

52 x 2 cm BC404 6.5 % 3in Ham-SBA

92 x 2 cm BC408 10.1 % 8in Ham-SBA w/ LG

142 x 2 cm BC404 9.2 % 8in ETL w/ LG

152 x 2 cm BC408 10.3 % 8in Ham-SBA w/ LG

20(hex) x 2 cm BC408 11.2 % 8in Ham-SBA w/ LG

** 202 x 2 cm PST (cast) 7.0 % 8in Photonis XP1886

** 202 x 10 cm PST (cast) 7.7 % 8in Photonis XP1886

Solid Scint. Results

** preliminary

Calorimeter R&D. Results so far.

Baseline design target!


Calorimeter R&D. Results so far.

Liquid Scint. Results

Scint Dimensions

(liquid)

FWHM @ 976 keV

PMT Size and Make

7.6 x 5 cm 7.6 % 3in Photonis XP5312


8.4 x 9.2 cm 7.3 % 5in Photonis XP2412


23(hex) x 9.2 cm 10.8 % 5in ETL 9390


Calorimeter R&D. Status.

• Four routes pursued– 8” PMT + plastic block– 8” PMT + liquid scintillator– 8” PMT + hybrid (liquid + plastic) scintillator– 2m scint. bar with 3” or 5” PMTs

• Target resolution 7-8% at 1 MeV (~4% FWHM at 3 MeV) reached for individual large baseline design blocks.

• PMTs– Working closely with manufacturers: Hamamatsu,

Photonis, ETL– Real breakthrough in high-QE PMTs from Hamamatsu and

Photonis: 43% QE.– Deep involvement in ultra-low background PMT

development (especially Photonis)

• Decision on calorimeter design in early 2009


Optimize length, wire material and diameter, read-out, gas mixture etcSeveral 1-cell and two 9-cell prototypes built and tested90-cell prototype being built

Tracker R&D

9-cell prototype in Manchester


Tracker studies. 1-cell prototypes.

370 cm

Plasma propagation timesAnode and cathode ring signals from ionization event

- Transverse position from electron drift times- Longitudinal position from plasma propagation times

- Wire diameter studies- Anode vs cathode rings only readoutfor longitudinal position reconstruction (anode readout feasible)- Electron drift times measured with laser - Cell diameter studies


Tracker studies. 9- and 90-cell prototypes.

12 wires per cell8 wires per cell

9-cell:End-cap design optimized for wiring robot feasible8-12 wires per cell workGeiger plateau > 200 VPlasma propagation efficiency ~100%

90-cellWill be built and wired by AugustTracking efficiency, cross-talk, ageing etcFinal SuperNEMO tracker design in early 2009.


Pair of end fittings

Anode wire feed mechanism

Clamp mechanism

Actuator mechanism

Tracker fully automated wiring.

Up to ~500,000 wires to be strung, crimped, terminatedWiring robot being developed in collaboration with Mullard Space Science Lab (UCL)


BiPo detector

• To measure contaminations of 208Tl and 214Bi in source foils before installation in SuperNEMO

• Goal: ~5kg of foil (12m2 , 40mg/cm2) in one month with a sensitivity of– 208Tl < 2 Bq/kg– 214Bi < 10Bq/kg

• BiPo-1 to measure scintillator surface contamination• Installed and commissioned in Canfranc in October’07• Temporarily relocated to Modane until Canfranc reopens• Extrapolated sensitivity from BiPo-1 first results:~1-10 Bq/kg • BiPo-2 results expected end 2008.

Background < 1 event/month!


SuperNEMO SuperNEMO Design StudyDesign Study

Schedule Summary2007 2008 2009 2010 2011 2012 2013

NEMO3 Running NEMO3 Running

Running full detector in 2014Running full detector in 2014

Target sensitivity (0.05-0.1 eV) in 2016/17Target sensitivity (0.05-0.1 eV) in 2016/17

construction of construction of 20 modules 20 modules

Installation Installation at new LSM at new LSM

Preparation of new Preparation of new LSM siteLSM site

BiPoBiPoinstallatioinstallatio

nn

BiPo1BiPo1Canfranc/LSMCanfranc/LSM

BiPoBiPoconstructionconstruction

BiPo BiPo running @ Canfrancrunning @ Canfranc

1-4 SuperNEMO modules1-4 SuperNEMO modules running at Canfrancrunning at Canfranc

SuperNEMO 1SuperNEMO 1stst module module

constructionconstruction

2014


• SuperNEMO: a chance to see a “smoking gun” evidence for 0 and directly disentangle underlying physics mechanism (V+A, Majoron, etc)

• Design Study addresses most critical issues– Energy resolution– Tracker optimization– Radiopurity

• Based on design study results full proposal for 100+ kg detector in 2010.– 82Se – baseline, 150Nd possible. – “Last minute” isotope change if e.g. CUORE sees the signal in 130Te.

• Start-up in stages due to modular approach– First module 2010/11– All 20 modules ~2013

• Target sensitivity: 50-100 meV by 2016/17

Summary

Documents

Probing neutrino mass with SuperNEMO Ruben Saakyan Ulisse at LSM Workshop 30 June 2008