SNO+SNO+

Mark ChenMark Chen

SNOLAB WorkshopSNOLAB Workshop

August 22, 2007August 22, 2007

OutlineOutline

science goalsscience goals– focusing on Nd double beta decayfocusing on Nd double beta decay

R&D activities and progressR&D activities and progress budget and schedulebudget and schedule

SNO+ OriginSNO+ Origin

SNO+ concept was born in the CFI SNO+ concept was born in the CFI Proposal for SNOLABProposal for SNOLAB– a deep lab is required to eliminate a deep lab is required to eliminate

cosmogenic cosmogenic 1111C background to the C background to the peppep solar neutrino signal in a liquid scintillator solar neutrino signal in a liquid scintillator detectordetector

part of the Subatomic Physics Five-part of the Subatomic Physics Five-Year Plan since 2001Year Plan since 2001

LOI to SNOLAB submitted April 2004LOI to SNOLAB submitted April 2004

Fill with Liquid Scintillator SNO plus liquid scintillator physics

program pep and CNO low energy solar neutrinos

tests the neutrino-matter interaction, sensitive to new physics

geo-neutrinos 240 km baseline reactor neutrino oscillations supernova neutrinos double beta decay

• …sometimes referred to as SNO++

• it is possible to add isotopes to liquid scintillator, for example– dissolve Xe gas– organometallic chemistry (Nd, Se, Te)

– dispersion of nanoparticles (Nd2O3, TeO2)

• we researched these options and decided that the best isotope and technique is to make a Nd-loaded liquid scintillator

SNO+ Double Beta Decay

150Nd

3.37 MeV endpoint (9.7 ± 0.7 ± 1.0) × 1018 yr

2half-life

measured by NEMO-III

isotopic abundance 5.6%1% natural Nd-loaded liquid scintillator in SNO+ has 560 kg of 150Nd compared to 37 g in NEMO-III

cost: $1000 per kg for metallic Nd; cheaper is NdCl3…$86 per kg for 1 tonne

table from F. Avignone Neutrino 2004

• a liquid scintillator detector has poor energy resolution; but enormous quantities of isotope (high statistics) and low backgrounds help compensate

• large, homogeneous liquid detector leads to well-defined background model– fewer types of material near fiducial volume– meters of self-shielding

• possibly source in–source out capability

SNO+ Double Beta Decay

• using the carboxylate technique that was developed originally for LENS and now also used for Gd-loaded scintillator

• we successfully loaded Nd into pseudocumene and in linear alkylbenzene (>1% concentration)

• with 1% Nd loading (natural Nd) we found very good neutrinoless double beta decay sensitivity…

Nd-Loaded Scintillator

0: 1000 events peryear with 1% naturalNd-loaded liquidscintillator in SNO++

Test <m> = 0.150 eV

maximum likelihood statistical test of the shape to extract 0 and 2 components…~240 units of 2 significance after only 1 year!

Klapdor-Kleingrothaus et al., Phys. Lett. B 586, 198, (2004)

simulation:one year of data

Nd-LS Synthesis

• solvent-solvent extraction method to synthesize metal-loaded liquid scintillator

• this method was used to make Nd-LS at both BNL and Queen’s laboratories

linear alkylbenzene (LAB)

(organic phase) Nd(RCOO)3

(aqueous phase)

Nd3+(Cl-)3 + 3RCOO- → Nd(RCOO)3

NH3 + RCOOH → NH4+ + RCOO-

300 400 500 600 7000.0

0.2

0.4

0.6

0.8

350 360 370 380 390 400 410 420 4300.00

0.01

0.02

0.03

0.04

0.05

0.06

AB

S

(nm)

Nd-LAB, 1.45% Nd Nd-PC, 1.01% Nd, BNL Nd-DIN, 1.5% Nd PPO emission

AB

S

(nm)

Nd in Various Scintillation Solvents

• you can see that 1% Nd-loaded scintillator is blue– because Nd absorbs light

• fortunately it is blue– it means the blue scintillation light can propagate through

• but, not enough light output in SNO+ if using 1% Nd loading

• BUT, with enriched Nd (e.g. enrich to 56% 150Nd up from 5.6%) could have the same neutrinoless double beta decay sensitivity using 0.1% Nd loading…

Light Output from Nd Scintillator

• at 1% loading (natural Nd), there is too much light absorption by Nd– 47±6 pe/MeV (from Monte

Carlo)

• at 0.1% loading (isotopically enriched to 56%) our Monte Carlo predicts– 400±21 pe/MeV (from Monte

Carlo)– good enough to do the

experiment

Light Output and Concentration

Nd-150 Consortium

SuperNEMO and SNO+, MOON and DCBA are supporting efforts to maintain an existing French AVLIS facility that is capable of making 100’s of kg of enriched Nda facility that enriched 204 kg of U (from 0.7%

to 2.5%) in several hundred hours

2000–2003 Program : Menphis facility

Design : 2001Building : 20021st test : early 20031st full scale exp. : june 2003

EvaporatorDye laser chainYag laserCopper vapor laser

AVLIS for 150Nd is Known

SNO+ Nd Summary So Far…

• SNO+ plans to deploy 0.1% Nd-loaded liquid scintillator– ~500 kg of 150Nd if enriched Nd– 56 kg of 150Nd if natural Nd

• light output: 400 pe/MeV corresponds to 6.4% resolution FWHM at 150Nd Q-value

• why Nd?– high Q-value is above most backgrounds– Ge: Majorana and GERDA– Xe: EXO, XMASS– Te: CUORE– Mo: MOON– Ca: CANDLES– Cd: C0BRA– Nd: SNO+

• how we search for double beta decay?– fit 2 and 0 known spectral shapes along with knowable background

shapes (mainly from internal Th)

SNO+ Double Beta SNO+ Double Beta SpectrumSpectrum

1 yr, 500 kg isotope, m = 150 meV

Statistical Sensitivity in Statistical Sensitivity in SNO+ SNO+

500 kg isotope 56 kg isotope

• 3 sigma detection on at least 5 out of 10 fake data sets• 2/0 decay rates are from Elliott & Vogel, Ann. Rev. Nucl. Part. Sci. 52, 115 (2002)

corresponds to 0.1% natural Nd LSin SNO+

0.1% Natural Nd Loading0.1% Natural Nd Loading

1yr, 1000kg natural, 150meV

• for 50% enriched 150Nd (0.1% Nd LS in SNO+)– 3 statistical sensitivity reaches 30 meV– 5 sensitivity of 40 meV after 3 years– for background levels (U, Th) in the Nd LS to be at the

same level as KamLAND scintillator

– systematic error in energy response will likely be the limit of the experiment and not the statistics

– preliminary studies show that we can understand the energy resolution systematics at the level required to preserve sensitivity down to 50 meV

Statistical Sensitivity

Stability of Nd-LAB

300 400 500 600 7000.0

0.2

0.4

0.6

0.8

350 360 370 380 390 400 410 420 4300.000

0.005

0.010

0.015

0.020

AB

S

(nm)

Nd-LAB, 1.45% Nd, 1 year Nd-LAB, 1.45% Nd PPO emission

AB

S

(nm)

no change in optical properties after >1 year

external 241Am

Compton edge 137Cs207Bi conversionelectrons

Nd LS Works!small Nd-LS detector with , , sources demonstrates it works as scintillator

Nd PurificationNd Purification

NdClNdCl33 needs to be purified needs to be purified putting Nd into the organic accomplishes putting Nd into the organic accomplishes

purification (U, Th don’t get loaded into the purification (U, Th don’t get loaded into the liquid scintillator)liquid scintillator)

Nd liquid scintillator: after synthesis it is Nd liquid scintillator: after synthesis it is possible to perform online loop purificationpossible to perform online loop purification

150150Nd enrichment also removes unwanted Nd enrichment also removes unwanted ThTh

Radio-purification goals: Radio-purification goals: 228228Th and Th and 228228Ra in 10 Ra in 10

tonnes of 10% Nd (in form tonnes of 10% Nd (in form of NdClof NdCl33 salt) down to salt) down to

<<110-14 g 232Th/g Nd

Raw NdClRaw NdCl33 salt salt

measurement: measurement: 228228Th Th equivalents to equivalents to 32±2532±2510-9 g g 232232Th/g NdTh/g Nd

A reduction of >106 is required!!!

Purification Spike Tests

• spike scintillator with 228Th (80 Bq) which decays to 212Pb• counted by β- coincidence liquid scintillation counting

Spike Test Results: Extraction Efficiencies of Th and Ra in 10% NdCl3 using HZrO and BaSO4

PurificationPurification

methodmethod

AdsorbentAdsorbent

ConcConc

Extraction efficiencyExtraction efficiency

228Th228Th 226Ra226Ra

HZrO mixed-inHZrO mixed-in

0.1 mg/g Zr0.1 mg/g Zr

0.44 mg/g Zr0.44 mg/g Zr

0.82 mg/g Zr0.82 mg/g Zr

<5%<5%

99.06±0.22%99.06±0.22%

99.89±0.02%99.89±0.02%

<10%<10%

30.7±5.7%30.7±5.7%

30.1±9.0% 30.1±9.0%

BaSO4 mixed-inBaSO4 mixed-in 1.0 mg/g Ba1.0 mg/g Ba 9.5±4.7% 9.5±4.7% 63.4±1.9% 63.4±1.9%

BaSO4 co-precipitationBaSO4 co-precipitation

0.49 mg/g Ba0.49 mg/g Ba

1.39 mg/g Ba1.39 mg/g Ba

20.4±4.4%20.4±4.4%

62.8±2.3%62.8±2.3%

97.2±0.2%97.2±0.2%

99.89±0.03%99.89±0.03%

factor of 1000 purification per pass achieved for both Th and Ra!

SNO+ Nd: Summary

• good sensitivity and very timely• homogeneous liquid, well defined background

model– large volume gives self-shielding– Q-value is above most backgrounds

• thus “insensitive” to internal radon backgrounds• thus insensitive to “external” backgrounds (2.6 MeV )

• Th, Ra purification techniques are effective• huge amounts of isotope, thus high statistics,

can work for double beta decay search– requires exquisite calibration and knowledge of

detector response

Low Energy Solar Neutrinos

p + p 2H + e+ + e p + e− + p 2H + e

2H + p 3He +

3He + 3He 4He + 2 p 3He + p 4He + e+ + e

3He + 4He 7Be +

7Be + e− 7Li + + e7Be + p 8B +

7Li + p + 8B 2 + e+ + e

p-p Solar Fusion Chain

• complete our understanding of neutrinos from the Sun

pep, CNO, 7Be, pp

CNO Cycle12C + p → 13N + 13N → 13C + e+ + e

13C + p → 14N + 14N + p → 15O + 15O → 15N + e+ + e

15N + p → 12C +

Ga, Cl and SNO Data – Distilled

Barger, Marfatia, Whisnant, hep-ph/0501247

deduce the survival probabilityhigh energy: directly from SNOmedium energy: Cl minus highlow energy: Ga minus high, medium

we observe that the survival probability for solar neutrinos versus energy is not yet accurately determined from existing experiments

transition between vacuum and matteroscillations in the Sun has not been accurately determined

there is even some tension in existing low and medium data…

x is 13

Things You Could Learn…with precision data from low energy solar neutrinos

• fix m2 with KamLAND data, vary 13 (with 12 fixed or varying)– low energy solar neutrino data helps constrain 13

• extract m2 from solar data, strongly affected by the position of the transition – low energy solar neutrino data are key – compare with m2 from KamLAND– neutrinos versus antineutrinos, tests CPT invariance

• compare position/shape of the transition at lower energy with the prediction from LMA MSW oscillations– might reveal deviations from Standard Model couplings (due to non-standard

interactions or coupling to a sterile neutrino admixture)

…and many of these studies have been done, all pointing to the fact that at the transition (between 1-2 MeV) there is sensitivityto new neutrino physics!

(e.g. Balantekin or Friedland, Peña-Garay, Lunardini, or Barger and colleagues…)

Neutrino-Matter Interaction

• best-fit oscillation parameters suggest MSW occurs

• but we have no direct evidence of MSW– day-night effect not observed– no spectral distortion for 8B ’s

• testing the vacuum-matter transition is sensitive to new physics

for m2 = 8 × 10−5 eV2, = 34°Ne at the centre of the Sun →E is 1-2 MeV Hamiltonian for neutrino propagation in the Sun

from Peña-Garay

• MSW is linear in GF and limits from -scattering experiments ( g2) aren’t that restrictive

• oscillation solutions with NSI can fit existing solar and atmospheric neutrino data…NSI not currently constrained

• new pep solar data would reveal NSI

Friedland, Lunardini, Peña-Garay, hep-ph/0402266

pep solar neutrinos are at the “sweet spot” to test for new physics

New Physicsgood fit with NSI

Mass-Varying Neutrinos

• cosmological connection: mass scale of neutrinos and the mass scale of dark energy are similar

• postulating a scalar field and neutrino coupling results in neutrinos whose mass varies with the background field (e.g. of other neutrinos)

• solar neutrinos affected?• pep : a sensitive probe

Barger, Huber, Marfatia, hep-ph/0502196

Fardon, Nelson, Weiner, hep-ph/0309800

pep

pep

SNO CC/NC

m2 = 8.0 × 10−5 eV2

tan2 = 0.45

SSM pep flux:uncertainty ±1.5%

known sourceknown cross section (-e scattering)→ measuring the rate gives the survivalprobability→ precision test

Why pep Solar Neutrinos?

observing the rise confirms MSW and our understanding of solar neutrinos

stat + syst + SSM errors estimated

for neutrino physics with lowenergy solar neutrinos, have toachieve precision similar to SNO or better…it’s no longer sufficient to just detect the neutrinos

pep solar neutrinos:E = 1.44 MeV…are at the right energy to search for new physics

these plots from the KamLAND proposal muon rate in KamLAND: 26,000 d−1 compared with SNO: 70 d−1

11C Cosmogenic Background

depth to reduce/eliminate 11C background

good light output from the scintillator studied the effect of varying the energy

resolution; found not a steep dependence radiopurity

control of Rn exposure because of 210Bi eliminate 40K internal contamination

Requirements for a Liquid Scintillator pep Solar Detector

Solar Signals with Solar Signals with BackgroundsBackgrounds

SNO+ Solar Neutrino Projected Capability with backgrounds at KamLAND levels

U, Th achieved 210Pb and 40K post-purification KamLAND targets external backgrounds

calculated based upon SNO external activities fiducial volume 450 cm

pep uncertainties <±5% statistical (signal extraction from background) ±3% systematic ±1.5% SSM e.g. it would be a measurement of the survival

probability at 1.44 MeV of 0.55 ± 0.03

pep Sensitivity Dependence on 210Pb

allowing 210Pb contamination to increase by large factors does not have a large impact on the pep statistical uncertainty

peppep and and 1313

solar neutrinos are solar neutrinos are complementary to complementary to long baseline and long baseline and reactor experiments reactor experiments for for 1313

hypothetical 5% hypothetical 5% stat. 3% syst. 1.5% stat. 3% syst. 1.5% SSM measurementSSM measurement

has discriminating has discriminating power for power for 1313

pep

antineutrino events e + p → e+ + n:• KamLAND: 33 events per year (1000 tons CH2) / 142 events reactor• SNO+: 44 events per year (1000 tons CH2) / 38 events reactor

Geo-Neutrino SignalGeo-Neutrino Signal

SNO+ geo-neutrinos and reactor background KamLAND geo-neutrino detection…July 28, 2005 in Nature

KamLAND

Reactor Neutrino OscillationsReactor Neutrino Oscillations50 km

Bruce 240 km

Pickering 340 km Darlington 360 kmoscillation spectral features depend on m2

and move as L/E

Clarence J. VirtueNSERC SNO+ Review - 27 November 2006

SNO+ vs. Super-Kamiokande

CC: (260) 41% (7000) 91%

(30) 4.7%

(10) 1.5%

NC: (60) 9.3% (410) 5%

(270) 42%

ES: (12) 1.9% (300) 4%

SN Neutrino Detection in SNO+

Steps Required: SNO → SNO+

• AV hold down

• liquid scintillator procurement

• scintillator purification

• “minor” upgrades– cover gas– electronics– DAQ– calibration

SNO+ Liquid Scintillator “new” liquid scintillator developed

linear alkylbenzene (LAB) compatible with acrylic, undiluted high light yield pure (light attenuation length in excess of 20 m at 420 nm) low cost high flash point 130°C safe low toxicity safe smallest scattering of all scintillating solvents investigated density = 0.86 g/cm3

metal-loading compatible SNO+ light output (photoelectrons/MeV) will be

approximately 3-4× that of KamLAND ~900 p.e./MeV for 54% PMT area coverage

Daya Bay and Hanohano plan to use LAB; others LENS, Double CHOOZ, LENA, NOA considering

SNO+ AV Hold Down

ExistingAV SupportRopes

SNO+ AV Hold Down

AV Hold DownRopes

ExistingAV SupportRopes

SNO+ R&D 2005SNO+ R&D 2005Proof of PrincipleProof of Principle linear alkylbenzene developed linear alkylbenzene developed

by SNO+ as the liquid by SNO+ as the liquid scintillatorscintillator

AV hold-down for specific AV hold-down for specific gravity 0.86 is feasible (study gravity 0.86 is feasible (study by Bob Brewer)by Bob Brewer)

double beta decay potential double beta decay potential investigatedinvestigated– made 1.0% Nd-loaded made 1.0% Nd-loaded

scintillatorscintillator

SNO+ 2006SNO+ 2006Expanded R&DExpanded R&D AV hold-down implementation plan developedAV hold-down implementation plan developed designs for cover gas and universal interface designs for cover gas and universal interface

being preparedbeing prepared radon daughter removal from acrylic studiedradon daughter removal from acrylic studied scintillator purification tests: scintillator purification tests: factor >1000factor >1000

achievedachieved initial conceptual design and layout for initial conceptual design and layout for

scintillator purification and handlingscintillator purification and handling simulations: signals and backgroundssimulations: signals and backgrounds continued scintillator-acrylic compatibility testscontinued scintillator-acrylic compatibility tests learned of the existence of French AVLIS learned of the existence of French AVLIS

facility for enriching neodymiumfacility for enriching neodymium

all major questions have been answered

SNO+ 2007 ContinuingSNO+ 2007 ContinuingResearch ProgressResearch Progress NdClNdCl33 purification tests: purification tests: factor ~1000factor ~1000 per per

pass achievedpass achieved scintillator purification and process scintillator purification and process

engineering: Phase I design completedengineering: Phase I design completed hold-down net designs being evaluatedhold-down net designs being evaluated finite-element analysis of the hold-down net finite-element analysis of the hold-down net

in progressin progress

SNO+ ActivitiesSNO+ Activities2007 and Beyond2007 and Beyond completed engineering of hold-down completed engineering of hold-down

system system engineering and building new engineering and building new

glovebox and calibration manipulator glovebox and calibration manipulator systemssystems

completed engineering of scintillator completed engineering of scintillator purification system by Dec 2007purification system by Dec 2007

DAQ upgrade to accommodate DAQ upgrade to accommodate higher rateshigher rates

Previous Analysis for SNO Prelim Hold-down Conceptused previous SNO calculation

Set of weights on bottom of cavity

SNO+ AV Hold-DownSNO+ AV Hold-Down

V. Strickland doing a new FEA V. Strickland doing a new FEA calculation of the hold-down netcalculation of the hold-down net– loading and buckling studyloading and buckling study– optimization of the designoptimization of the design

flat ropes, round ropesflat ropes, round ropes number of ropesnumber of ropes rope spacingrope spacing circumferential rope(s) placementcircumferential rope(s) placement ……

S. Florian engineeering the PSUP S. Florian engineeering the PSUP penetrations and hold-down anchorspenetrations and hold-down anchors

Rope ConfigurationRope Configuration P. Harvey studying rope tensions and P. Harvey studying rope tensions and

geometrical placement for PSUP penetrationsgeometrical placement for PSUP penetrations

SNO+ Universal SNO+ Universal InterfaceInterface glove boxglove box cover gascover gas calibration manipulatorcalibration manipulator feedthrough for AV pipesfeedthrough for AV pipes

SNO Cover Gas SNO Cover Gas SystemSystem

SNO covergas system was not sealed; dealt with pressure swings by continuous venting

for SNO+ improvements to this system are being developed

SNO Calibration SourceSNO Calibration Source ManipulatorManipulator

Radon/Light Barrier

Umbilicals Manipulation Detector Interface

Accuracy

< 2 cm single axis

~ 5 cm triple axis

Remote Operation/Interlocks

Stringent Cleanliness Requirements

New Glove BoxNew Glove Box

SNO+ Electronics Upgrades Front End (with no hardware changes):

Re-tune integration time from ~420ns -> ~1s (max possible without hardware change)

Re-adjust short and long integration times for better match to scintillation time constants

Adjust FPGA code to optimize for higher hit rate

Front End (possible hardware changes):

Replace biasing resistors for lower trigger current.

Replace memory controller and 4 MByte memory SIMMS for larger event buffering.

Re-adjust references for ADCs to match higher charges.

SNO+ NSERC Review 27 Nov 2006Fraser Duncan, SNOLAB

SNO+ Electronics Upgrades Trigger (hardware changes):

Need re-design of final analog summing board to handle higher currents.

May also want to implement active baseline restoration to improve stability.

Replace analog measurement board with full transient digitizer to store energy sum trace with each event, possibly other trigger sum traces also.

Miscellaneous

Various small upgrades to electronics and electrics in the detector (items that were low priority during SNO operations).

SNO+ NSERC Review 27 Nov 2006Fraser Duncan, SNOLAB

Data Flow Upgrades

SNO+ NSERC Review 27 Nov 2006Fraser Duncan, SNOLAB

Replace existingSun Sparc Ultra 1with new system(Mac or Linux)

Possibly replacesingle ECPU withmultiple processors

Possibly replaceXL1/XL2 interfacecards with higherthroughput pair

Data Flow

DAQ Upgrades

SNO+ NSERC Review 27 Nov 2006Fraser Duncan, SNOLAB

Replace Mac OS9 system with OSX.Rewrite DAQ program(SHaRC) for OSX

Hardware Control

Improve remotemonitoring toolsfor remotedetector operation

OffSite

PMT Failures

Fraser Duncan, SNOLAB SNO+ NSERC Review 27 Nov 2006

Number of PMT Failures Between June 18, 1999 and Nov 23, 2006

00/01 01/01 02/01 03/01 04/01 05/01 06/01 07/01

Date

• Similar to water fill rate• Failures seem correlated with HV• No effect due to raised HV (+50 V Oct 2004)

Dead T

ubes

100

700

200

300

400

500

600

800

Turn

off

for

NC

D Inst

alla

tion

Turn

on a

fter

NC

D Inst

alla

tion

0.8% / yr

72 PMT FailuresPer Year

Electronics Failures Failure of SNO electronics have been tracked.

SNO+ NSERC Review 27 Nov 2006Fraser Duncan, SNOLAB

Motherboards DaughtercardsMain

Pow

er

LV

Pow

er S

upplie

s

HV

Supply

MTC

/D

MTC

/A (fi

x)

XL2

CTC

& e

sum

repairs

HV

backpla

in

HV

overh

aull

PM

TIC

(exclu

de W

EB

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B re

pair

PM

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d

PM

T re

sure

ctio

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L.V

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LV

Monito

r

FIF

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pairs

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pairs

tota

l repairs

tota

l repla

ced

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pairs

Cle

an D

M

Fix

bad c

hannels

Bad e

ca/p

ca re

pla

ce

tota

l repairs

Tota

l repla

ced

tota

l Repairs

Tota

l MB

/DB

repla

ced

Tota

l DM

Failu

res

2001 0 1 0 2 0 4 1 2 3 3 61 116 0 8 0 20 0 3 31 11 1 0 0 0 1 19 164 30 202002 1 0 1 0 0 1 2 0 0 5 103 153 0 5 10 16 3 1 35 15 3 0 0 14 3 22 201 37 342003 0 1 0 0 2 1 0 0 26 30 72 131 50 2 11 3 0 2 18 5 0 2 0 16 2 25 261 30 232004 0 0 1 0 1 1 7 0 1 2 29 52 0 5 2 4 0 0 11 8 1 4 58 8 63 19 139 27 162005 1 0 0 0 1 2 0 0 0 2 47 86 0 7 7 10 0 0 24 8 1 0 0 8 1 15 117 23 162006 0 0 0 0 0 0 0 0 0 1 21 30 0 10 9 5 5 1 23 1 0 0 0 3 0 7 54 8 13

Total 2 2 2 2 4 9 10 2 30 43 333 568 50 37 39 58 8 7 142 48 6 6 58 49 70 107 936 155 122

Daughter Cards (8 chs/card) are key components.

There are few conventional spares of some of the components.

Current failure rates are ~11 DCs/yr = 90 ch per year

Approximately the same rate as PMT failures.

Electronics Spares

SNO+ NSERC Review 27 Nov 2006Fraser Duncan, SNOLAB

Several actions will be taken to bolster the electronics spares:

1) Salvage “seconds” - components that were slightly outside the original acceptance criteria; and recover components for the “bone piles”.

2) Consolidate the dead PMTs in each rack. This will release

~30 Motherboards ~120 Daughtercards ~30 PMTICs

This would produce ~6yrs of spare components if no further action was taken.

As PMTs and electronics channels fail during SNO+ operations, periodically consolidate failed PMTs and channels.

Scintillator Purification

prelim design completed by KMPS (engineering company that designed the Borexino scintillator purification)

sizing completed, operating temperatures and pressures, flow rates calculated, performance simulated…

SNO+ Project Costs SNO+ Project Costs

estimated total estimated total costscostsExpenses: Cash Flow:

Canadian Costs to Convert SNO to SNO+ 2007/08 2008/09 $M $M $M procure liquid scintillator 2.00 0.00 2.00 AV hold-down conversion 2.25 0.30 1.95 scintillator purification plant 7.63 0.30 7.33 cover gas and universal interface 0.30 0.20 0.00 TOTAL 12.18 0.80 11.28 US Contribution (in addition to US SNO equipment) electronics and DAQ upgrade 0.5 obtain enriched Nd-150 4.00 0.00 4.00 TOTAL with Nd 16.18

Broadbrush ScheduleBroadbrush Schedule

Apr 2007: $400k NSERC funds received for continued developmentApr 2007: $400k NSERC funds received for continued development– expenditures on AV and cavity inspection, light water systemexpenditures on AV and cavity inspection, light water system– Phase I scintillator purification and process engineeringPhase I scintillator purification and process engineering– radon-reduced air systemradon-reduced air system

Aug-Sep 2007: begin light water refillAug-Sep 2007: begin light water refill Oct 1, 2007: submit NSERC portion of the SNO+ capital proposalOct 1, 2007: submit NSERC portion of the SNO+ capital proposal Oct 2007: AV contains light waterOct 2007: AV contains light water Q4 2007: $400k FedNor funds for continued development availableQ4 2007: $400k FedNor funds for continued development available Dec 2007-Jan 2008: submit capital proposal to CFIDec 2007-Jan 2008: submit capital proposal to CFI

Feb 2008: begin installation of radon-free airFeb 2008: begin installation of radon-free air Q2 2008: start of capital fundsQ2 2008: start of capital funds Q2 2008: begin construction of scintillator purification modulesQ2 2008: begin construction of scintillator purification modules Jun 2008: install “floating dock” inside AV using radon-free airJun 2008: install “floating dock” inside AV using radon-free air Jun 2008: start draining light water in AV; sand AV surfaces as water Jun 2008: start draining light water in AV; sand AV surfaces as water

is drainedis drained Sep 2008, AV is sanded, atmosphere is radon-free air; withdraw Sep 2008, AV is sanded, atmosphere is radon-free air; withdraw

floating docks, prepare AV sealfloating docks, prepare AV seal construction of AV hold-down follows; installation of scintillator construction of AV hold-down follows; installation of scintillator

process and purification; install new universal interface…process and purification; install new universal interface…

SNO+ Nd Broadbrush schedule

• end of 2009: fill and run with pure scintillator

• 2010: add Nd

• 2011: below 100 meV sensitivity reached if natural Nd and below 50 meV reached if enriched Nd

SNO+ Special SNO+ Special RequirementsRequirements 1000 tons of linear alkylbenzene1000 tons of linear alkylbenzene

– high flash point (130°C) high flash point (130°C) safesafe– low toxicity low toxicity safesafe

not classified as hazardous material for not classified as hazardous material for transportationtransportation

handling large quantity is a special requirementhandling large quantity is a special requirement– use SNO railcars for transportation: surface to use SNO railcars for transportation: surface to

detectordetector ~200 kW heating and <50 tons cooling ~200 kW heating and <50 tons cooling

limitations have been observed in the design of limitations have been observed in the design of the distillationthe distillation

11

0pseudocumene (2 4 0)diesel (0 2 0)

SNO+ is Already at SNO+ is Already at SNOLABSNOLAB scintillator purification replaces heavy scintillator purification replaces heavy

water purificationwater purification special requirement of 1000 tons LABspecial requirement of 1000 tons LAB

– prelim process design completedprelim process design completed– site visit to Petresa in Sep 2007site visit to Petresa in Sep 2007– preparation of documents describing the preparation of documents describing the

handling protocols for INCO and SNOLAB handling protocols for INCO and SNOLAB approvalapproval

otherwise SNO+ is like SNOotherwise SNO+ is like SNO

SNO+ Year 1 Activities SNO+ Year 1 Activities at SNOLABat SNOLAB inspection of the cavityinspection of the cavity inspection of the acrylic vesselinspection of the acrylic vessel modifications to the universal interface modifications to the universal interface

(glove box on top of the detector)(glove box on top of the detector) modifications to the cover gas (for both modifications to the cover gas (for both

installation and eventual running)installation and eventual running) deployment of some hardware for the cavity deployment of some hardware for the cavity

accessaccess completed engineering for the hold-down completed engineering for the hold-down

system and the scintillator purification system and the scintillator purification processprocess

consolidation of electronicsconsolidation of electronics

SNO+ Year 2 at SNO+ Year 2 at SNOLABSNOLAB construction: AV hold-downconstruction: AV hold-down construction scintillator purification construction scintillator purification

system (and fluid handling)system (and fluid handling) scintillator procurement contractsscintillator procurement contracts electronics/DAQ upgradeselectronics/DAQ upgrades

……aim for end of 2009 detector fillingaim for end of 2009 detector filling

Summary PointsSummary Points

diverse and exciting neutrino physicsdiverse and exciting neutrino physics SNO+ double beta decay is competitive and could SNO+ double beta decay is competitive and could

be leading the field with an early startbe leading the field with an early start SNO+ is the most interesting solar neutrino SNO+ is the most interesting solar neutrino

experiment to be done post-SNOexperiment to be done post-SNO SNO+ geo-neutrinos will be a SNO+ geo-neutrinos will be a NatureNature publication publication

of considerable popular science interest…for free!of considerable popular science interest…for free! SNO+ reactor neutrino “oscillation dip moves as SNO+ reactor neutrino “oscillation dip moves as

L/E” will be an easy L/E” will be an easy PRLPRL publication…for free! publication…for free! we have the required technical skills in our teamwe have the required technical skills in our team

– SNO+ includes KamLAND and Borexino members and SNO+ includes KamLAND and Borexino members and experienceexperience

we have proven SNO operations capabilitywe have proven SNO operations capability much of the development activity is much of the development activity is

straightforward engineering; nothing all that straightforward engineering; nothing all that exotic is being proposedexotic is being proposed

SNO+ CollaborationQueen’s

M. Boulay, M. Chen, X. Dai, E. Guillian, P. Harvey, C. Kraus, C. Lan,A. McDonald, V. Novikov, S. Quirk, P. Skensved, A. Wright

AlbertaA. Hallin, C. Krauss

CarletonK. Graham

LaurentianD. Hallman, C. Virtue

SNOLABB. Cleveland, F. Duncan, R. Ford, N. Gagnon, J. Heise, C. Jillings, I. Lawson

Brookhaven National LabR. Hahn, Y. Williamson, M. Yeh

Idaho State UniversityK. Keeter, J. Popp, E. Tatar

University of PennsylvaniaG. Beier, H. Deng, B. Heintzelman, J. Secrest

University of Texas at AustinJ. Klein

University of WashingtonN. Tolich, J. Wilkerson

University of SussexK. Zuber

LIP LisbonS. Andringa, N. Barros, J. Maneira

Nd Matrix Elements

• from Elliott and Vogel, hep-ph/0202264 v1 (2002)– 0.1 is Staudt, Muto and Klapdor– 0.2 is Faessler and Simkovic; Toivanen and Suhonen

• from Rodin et al., corrected (2007) value is 0.2-0.3