1. SNO+ Mark Chen SNOLAB Workshop August 22, 2007

2. Outline science goals science goals –focusing on Nd double beta decay R&D activities and progress R&D activities and progress budget and schedule budget and schedule

3. SNO+ Origin SNO+ concept was born in the CFI Proposal for SNOLAB SNO+ concept was born in the CFI Proposal for SNOLAB –a deep lab is required to eliminate cosmogenic 11 C background to the pep solar neutrino signal in a liquid scintillator detector part of the Subatomic Physics Five-Year Plan since 2001 part of the Subatomic Physics Five-Year Plan since 2001 LOI to SNOLAB submitted April 2004 LOI to SNOLAB submitted April 2004

4. 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

5. …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 (Nd 2 O 3, TeO 2 ) we researched these options and decided that the best isotope and technique is to make a Nd-loaded liquid scintillator SNO+ Double Beta Decay

6. 150 Nd 3.37 MeV endpoint (9.7 ± 0.7 ± 1.0) × 10 18 yr 2  half-life measured by NEMO-III isotopic abundance 5.6% 1% natural Nd-loaded liquid scintillator in SNO+ has 560 kg of 150 Nd compared to 37 g in NEMO-III cost: $1000 per kg for metallic Nd; cheaper is NdCl 3 …$86 per kg for 1 tonne table from F. Avignone Neutrino 2004

7. 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

8. 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

9. 0 : 1000 events per year with 1% natural Nd-loaded liquid scintillator in SNO++ Test = 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

10. 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) Nd 3+ (Cl - ) 3 + 3RCOO - → Nd(RCOO) 3 NH 3 + RCOOH → NH 4+ + RCOO -

11. Nd in Various Scintillation Solvents

12. 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% 150 Nd up from 5.6%) could have the same neutrinoless double beta decay sensitivity using 0.1% Nd loading… Light Output from Nd Scintillator

13. 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

14. 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 Nd  a facility that enriched 204 kg of U (from 0.7% to 2.5%) in several hundred hours

15. 2000–2003 Program : Menphis facility Design : 2001 Building : 2002 1 st test : early 2003 1 st full scale exp. : june 2003 Evaporator Dye laser chain Yag laser Copper vapor laser

16. AVLIS for 150 Nd is Known

17. SNO+ Nd Summary So Far… SNO+ plans to deploy 0.1% Nd-loaded liquid scintillator –~500 kg of 150 Nd if enriched Nd –56 kg of 150 Nd if natural Nd light output: 400 pe/MeV corresponds to 6.4% resolution FWHM at 150 Nd 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)

18. SNO+ Double Beta Spectrum 1 yr, 500 kg isotope, m = 150 meV

19. Statistical Sensitivity in 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 LS in SNO+

20. 0.1% Natural Nd Loading 1yr, 1000kg natural, 150meV

21. for 50% enriched 150 Nd (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

22. Stability of Nd-LAB no change in optical properties after >1 year

23. external 241 Am  Compton edge 137 Cs 207 Bi conversion electrons Nd LS Works! small Nd-LS detector with , ,  sources demonstrates it works as scintillator

24. Nd Purification NdCl 3 needs to be purified NdCl 3 needs to be purified putting Nd into the organic accomplishes purification (U, Th don’t get loaded into the liquid scintillator) putting Nd into the organic accomplishes purification (U, Th don’t get loaded into the liquid scintillator) Nd liquid scintillator: after synthesis it is possible to perform online loop purification Nd liquid scintillator: after synthesis it is possible to perform online loop purification 150 Nd enrichment also removes unwanted Th 150 Nd enrichment also removes unwanted Th

25. Radio-purification goals: 228 Th and 228 Ra in 10 tonnes of 10% Nd (in form of NdCl 3 salt) down to < 228 Th and 228 Ra in 10 tonnes of 10% Nd (in form of NdCl 3 salt) down to <1  10 -14 g 232 Th/g Nd Raw NdCl 3 salt measurement: 228 Th equivalents to 32±25 g 232 Th/g Nd Raw NdCl 3 salt measurement: 228 Th equivalents to 32±25  10 -9 g 232 Th/g Nd A reduction of >10 6 is required!!!

26. Purification Spike Tests spike scintillator with 228 Th (80 Bq) which decays to 212 Pb counted by β-  coincidence liquid scintillation counting

27. Spike Test Results: Extraction Efficiencies of Th and Ra in 10% NdCl 3 using HZrO and BaSO 4 PurificationmethodAdsorbentConc Extraction efficiency 228Th226Ra HZrO mixed-in 0.1 mg/g Zr 0.44 mg/g Zr 0.82 mg/g Zr <5%99.06±0.22%99.89±0.02%<10%30.7±5.7%30.1±9.0% BaSO4 mixed-in 1.0 mg/g Ba 9.5±4.7%63.4±1.9% BaSO4 co-precipitation 0.49 mg/g Ba 1.39 mg/g Ba 20.4±4.4%62.8±2.3%97.2±0.2%99.89±0.03% factor of 1000 purification per pass achieved for both Th and Ra!

28. 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

29. Low Energy Solar Neutrinos p + p  2 H + e + + e p + e − + p  2 H + e 2 H + p  3 He +  3 He + 3 He  4 He + 2 p 3 He + p  4 He + e + + e 3 He + 4 He  7 Be +  7 Be + e −  7 Li +  + e 7 Be + p  8 B +  7 Li + p   +  8 B  2  + e + + e p-p Solar Fusion Chain complete our understanding of neutrinos from the Sun pep, CNO, 7 Be, pp CNO Cycle 12 C + p → 13 N +  13 N → 13 C + e + + e 13 C + p → 14 N +  14 N + p → 15 O +  15 O → 15 N + e + + e 15 N + p → 12 C + 

30. Ga, Cl and SNO Data – Distilled Barger, Marfatia, Whisnant, hep-ph/0501247 deduce the survival probability high energy: directly from SNO medium energy: Cl minus high low 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 matter oscillations in the Sun has not been accurately determined there is even some tension in existing low and medium data…  x is  13

31. Things You Could Learn …with precision data from low energy solar neutrinos fix  m 2 with KamLAND data, vary  13 (with  12 fixed or varying) –low energy solar neutrino data helps constrain  13 extract  m 2 from solar data, strongly affected by the position of the transition – low energy solar neutrino data are key – compare with  m 2 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 sensitivity to new neutrino physics! (e.g. Balantekin or Friedland, Peña-Garay, Lunardini, or Barger and colleagues…)

32. 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 8 B ’s testing the vacuum-matter transition is sensitive to new physics for  m 2 = 8 × 10 −5 eV 2,  = 34° N e at the centre of the Sun → E is 1-2 MeV Hamiltonian for neutrino propagation in the Sun from Peña-Garay

33. MSW is linear in G F and limits from -scattering experiments (  g 2 ) 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 Physics good fit with NSI

34. 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

35. SNO CC/NC  m 2 = 8.0 × 10 −5 eV 2 tan 2  = 0.45 SSM pep flux: uncertainty ±1.5% known source known cross section ( -e scattering) → measuring the rate gives the survival probability → 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 low energy solar neutrinos, have to achieve 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

36. these plots from the KamLAND proposal muon rate in KamLAND: 26,000 d −1 compared with SNO: 70 d −1 11 C Cosmogenic Background

37.  depth to reduce/eliminate 11 C 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 210 Bi eliminate 40 K internal contamination Requirements for a Liquid Scintillator pep Solar Detector

38. Solar Signals with Backgrounds

39. SNO+ Solar Neutrino Projected Capability  with backgrounds at KamLAND levels U, Th achieved 210 Pb and 40 K 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

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

41. pep and  13 solar neutrinos are complementary to long baseline and reactor experiments for  13 solar neutrinos are complementary to long baseline and reactor experiments for  13 hypothetical 5% stat. 3% syst. 1.5% SSM measurement hypothetical 5% stat. 3% syst. 1.5% SSM measurement has discriminating power for  13 has discriminating power for  13 pep

42. antineutrino events e + p → e + + n: KamLAND: 33 events per year (1000 tons CH 2 ) / 142 events reactor SNO+: 44 events per year (1000 tons CH 2 ) / 38 events reactor Geo-Neutrino Signal SNO+ geo-neutrinos and reactor backgroundKamLAND geo-neutrino detection…July 28, 2005 in Nature KamLAND

43. Reactor Neutrino Oscillations 50 km Bruce 240 km Pickering 340 km Darlington 360 km oscillation spectral features depend on  m 2 and move as L/E

44. Clarence J. Virtue NSERC 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+

45. Steps Required: SNO → SNO+ AV hold down liquid scintillator procurement scintillator purification “minor” upgrades –cover gas –electronics –DAQ –calibration

46. 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°Csafe  low toxicity safe  smallest scattering of all scintillating solvents investigated  density  = 0.86 g/cm 3  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, NO A considering

47. SNO+ AV Hold Down Existing AV Support Ropes

48. SNO+ AV Hold Down AV Hold Down Ropes Existing AV Support Ropes

49. SNO+ R&D 2005 Proof of Principle linear alkylbenzene developed by SNO+ as the liquid scintillator linear alkylbenzene developed by SNO+ as the liquid scintillator AV hold-down for specific gravity 0.86 is feasible (study by Bob Brewer) AV hold-down for specific gravity 0.86 is feasible (study by Bob Brewer) double beta decay potential investigated double beta decay potential investigated –made 1.0% Nd-loaded scintillator

50. SNO+ 2006 Expanded R&D AV hold-down implementation plan developed AV hold-down implementation plan developed designs for cover gas and universal interface being prepared designs for cover gas and universal interface being prepared radon daughter removal from acrylic studied radon daughter removal from acrylic studied scintillator purification tests: factor >1000 achieved scintillator purification tests: factor >1000 achieved initial conceptual design and layout for scintillator purification and handling initial conceptual design and layout for scintillator purification and handling simulations: signals and backgrounds simulations: signals and backgrounds continued scintillator-acrylic compatibility tests continued scintillator-acrylic compatibility tests learned of the existence of French AVLIS facility for enriching neodymium learned of the existence of French AVLIS facility for enriching neodymium all major questions have been answered

51. SNO+ 2007 Continuing Research Progress NdCl 3 purification tests: factor ~1000 per pass achieved NdCl 3 purification tests: factor ~1000 per pass achieved scintillator purification and process engineering: Phase I design completed scintillator purification and process engineering: Phase I design completed hold-down net designs being evaluated hold-down net designs being evaluated finite-element analysis of the hold-down net in progress finite-element analysis of the hold-down net in progress

52. SNO+ Activities 2007 and Beyond completed engineering of hold-down system completed engineering of hold-down system engineering and building new glovebox and calibration manipulator systems engineering and building new glovebox and calibration manipulator systems completed engineering of scintillator purification system by Dec 2007 completed engineering of scintillator purification system by Dec 2007 DAQ upgrade to accommodate higher rates DAQ upgrade to accommodate higher rates

53. Previous Analysis for SNOPrelim Hold-down Concept used previous SNO calculation Set of weights on bottom of cavity

54. SNO+ AV Hold-Down V. Strickland doing a new FEA calculation of the hold-down net V. Strickland doing a new FEA calculation of the hold-down net –loading and buckling study –optimization of the design flat ropes, round ropes flat ropes, round ropes number of ropes number of ropes rope spacing rope spacing circumferential rope(s) placement circumferential rope(s) placement … S. Florian engineeering the PSUP penetrations and hold-down anchors S. Florian engineeering the PSUP penetrations and hold-down anchors

55. Rope Configuration P. Harvey studying rope tensions and geometrical placement for PSUP penetrations P. Harvey studying rope tensions and geometrical placement for PSUP penetrations

56. SNO+ Universal Interface glove box glove box cover gas cover gas calibration manipulator calibration manipulator feedthrough for AV pipes feedthrough for AV pipes

57. SNO Cover Gas System SNO Cover Gas System SNO covergas system was not sealed; dealt with pressure swings by continuous venting for SNO+ improvements to this system are being developed

58. SNO Calibration Source Manipulator Radon/Light Barrier UmbilicalsManipulationDetector Interface Accuracy < 2 cm single axis ~ 5 cm triple axis Remote Operation/Interlocks Stringent Cleanliness Requirements

59. New Glove Box

60. SNO+ Electronics Upgrades Front End (with no hardware changes):  Re-tune integration time from ~420ns -> ~1  s (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

61. 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

62. Data Flow Upgrades SNO+ NSERC Review 27 Nov 2006Fraser Duncan, SNOLAB Replace existing Sun Sparc Ultra 1 with new system (Mac or Linux) Possibly replace single ECPU with multiple processors Possibly replace XL1/XL2 interface cards with higher throughput pair Data Flow

63. 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 remote monitoring tools for remote detector operation Off Site

64. PMT Failures Fraser Duncan, SNOLABSNO+ 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 Tubes 100 700 200 300 400 500 600 800 Turn off for NCD Installation Turn on after NCD Installation 0.8% / yr 72 PMT Failures Per Year

65. Electronics Failures Failure of SNO electronics have been tracked. SNO+ NSERC Review 27 Nov 2006Fraser Duncan, SNOLAB 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.

66. 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.

67. 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…

68. SNO+ Project Costs estimated total costs

69. Broadbrush Schedule Apr 2007: $400k NSERC funds received for continued development Apr 2007: $400k NSERC funds received for continued development –expenditures on AV and cavity inspection, light water system –Phase I scintillator purification and process engineering –radon-reduced air system Aug-Sep 2007: begin light water refill Aug-Sep 2007: begin light water refill Oct 1, 2007: submit NSERC portion of the SNO+ capital proposal Oct 1, 2007: submit NSERC portion of the SNO+ capital proposal Oct 2007: AV contains light water Oct 2007: AV contains light water Q4 2007: $400k FedNor funds for continued development available Q4 2007: $400k FedNor funds for continued development available Dec 2007-Jan 2008: submit capital proposal to CFI Dec 2007-Jan 2008: submit capital proposal to CFI Feb 2008: begin installation of radon-free air Feb 2008: begin installation of radon-free air Q2 2008: start of capital funds Q2 2008: start of capital funds Q2 2008: begin construction of scintillator purification modules Q2 2008: begin construction of scintillator purification modules Jun 2008: install “floating dock” inside AV using radon-free air Jun 2008: install “floating dock” inside AV using radon-free air Jun 2008: start draining light water in AV; sand AV surfaces as water is drained Jun 2008: start draining light water in AV; sand AV surfaces as water is drained Sep 2008, AV is sanded, atmosphere is radon-free air; withdraw floating docks, prepare AV seal Sep 2008, AV is sanded, atmosphere is radon-free air; withdraw floating docks, prepare AV seal construction of AV hold-down follows; installation of scintillator process and purification; install new universal interface… construction of AV hold-down follows; installation of scintillator process and purification; install new universal interface…

70. 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

71. SNO+ Special Requirements 1000 tons of linear alkylbenzene 1000 tons of linear alkylbenzene –high flash point (130°C) safe –low toxicity safe not classified as hazardous material for transportation not classified as hazardous material for transportation handling large quantity is a special requirement handling large quantity is a special requirement –use SNO railcars for transportation: surface to detector ~200 kW heating and <50 tons cooling limitations have been observed in the design of the distillation ~200 kW heating and <50 tons cooling limitations have been observed in the design of the distillation 1 1 0 pseudocumene (2 4 0) diesel (0 2 0)

72. SNO+ is Already at SNOLAB scintillator purification replaces heavy water purification scintillator purification replaces heavy water purification special requirement of 1000 tons LAB special requirement of 1000 tons LAB –prelim process design completed –site visit to Petresa in Sep 2007 –preparation of documents describing the handling protocols for INCO and SNOLAB approval otherwise SNO+ is like SNO otherwise SNO+ is like SNO

73. SNO+ Year 1 Activities at SNOLAB inspection of the cavity inspection of the cavity inspection of the acrylic vessel inspection of the acrylic vessel modifications to the universal interface (glove box on top of the detector) modifications to the universal interface (glove box on top of the detector) modifications to the cover gas (for both installation and eventual running) modifications to the cover gas (for both installation and eventual running) deployment of some hardware for the cavity access deployment of some hardware for the cavity access completed engineering for the hold-down system and the scintillator purification process completed engineering for the hold-down system and the scintillator purification process consolidation of electronics consolidation of electronics

74. SNO+ Year 2 at SNOLAB construction: AV hold-down construction: AV hold-down construction scintillator purification system (and fluid handling) construction scintillator purification system (and fluid handling) scintillator procurement contracts scintillator procurement contracts electronics/DAQ upgrades electronics/DAQ upgrades …aim for end of 2009 detector filling …aim for end of 2009 detector filling

75. Summary Points diverse and exciting neutrino physics diverse and exciting neutrino physics SNO+ double beta decay is competitive and could be leading the field with an early start SNO+ double beta decay is competitive and could be leading the field with an early start SNO+ is the most interesting solar neutrino experiment to be done post-SNO SNO+ is the most interesting solar neutrino experiment to be done post-SNO SNO+ geo-neutrinos will be a Nature publication of considerable popular science interest…for free! SNO+ geo-neutrinos will be a Nature publication of considerable popular science interest…for free! SNO+ reactor neutrino “oscillation dip moves as L/E” will be an easy PRL publication…for free! SNO+ reactor neutrino “oscillation dip moves as L/E” will be an easy PRL publication…for free! we have the required technical skills in our team we have the required technical skills in our team –SNO+ includes KamLAND and Borexino members and experience we have proven SNO operations capability we have proven SNO operations capability much of the development activity is straightforward engineering; nothing all that exotic is being proposed much of the development activity is straightforward engineering; nothing all that exotic is being proposed

76. SNO+ Collaboration Queen’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 Alberta A. Hallin, C. Krauss Carleton K. Graham Laurentian D. Hallman, C. Virtue SNOLAB B. Cleveland, F. Duncan, R. Ford, N. Gagnon, J. Heise, C. Jillings, I. Lawson Brookhaven National Lab R. Hahn, Y. Williamson, M. Yeh Idaho State University K. Keeter, J. Popp, E. Tatar University of Pennsylvania G. Beier, H. Deng, B. Heintzelman, J. Secrest University of Texas at Austin J. Klein University of Washington N. Tolich, J. Wilkerson University of Sussex K. Zuber LIP Lisbon S. Andringa, N. Barros, J. Maneira

77. 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