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TRIUMF and UBC in the SNO Experiment McDonald, Art May 6, 2008

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Erich W. VogtCanadian Statesmanin Sub-atomic PhysicsTRIUMF and UBC in the SNO Project Faculty, and TRIUMF Scientists: Chris Waltham, Rich Helmer, Scott OserPost Docs: Salvador Gil, Rob Komar , Thomas Kutter, Juergen Wendland, Blair Jamieson, Ron Schubank, Reena Meijer DreesGraduate Students: Alan Poon, Jaret Heise, Christian Nally, Tyron Tsui, Louis McGarry, Guy OuelletteUndergraduates: Mitch Crowe, Bryce Croll, Ben Short, Ivan Sham, Jamil Sharif, Tudor Costin, Dave Branch, Jonathan Harris, Rob Newman, Vicky Valiani, KiaraMoran, Siong Ng, Chris Nell, Chris Callendar, Sam Marchand, Janice BoyceBahcall et al., SNOFlavour Change for Solar NeutrinosSolar Model Flux CalculationsCNOSNO was designed to observe separately νe and all neutrino types to determine if low νe fluxescome from flavor change or solar models Previous Experiments Sensitiveto Electron NeutrinosUnique Signatures in SNO (D2O)Charged-Current (CC)νe+d → e-+p+pEthresh = 1.4 MeVνe onlyElastic Scattering (ES) (D2O & H2O)νx+e-→ νx+e-νx, but enhanced for νeNeutral-Current (NC)νx+d→ νx+n+pEthresh = 2.2 MeVEqually sensitive to νe νμ ντ3 ways todetect neutronsPhase II (salt)July 01 - Sep. 03Phase III (3He)Nov. 04-Dec. 06Phase I (D2O)Nov. 99 - May 01SNO: 3 neutron (NC) detectionmethods (systematically different) n captures on2H(n, γ)3HEffc. ~14.4% NC and CC separation by energy, radial, and directional distributions40 proportional counters3He(n, p)3HEffc. ~ 30% captureMeasure NC rate with entirely different detection system.2 t NaCl. n captures on35Cl(n, γ)36ClEffc. ~40% NC and CC separation by event isotropy36Cl35Cl+n8.6 MeV3H2H+n 6.25 MeVn + 3He → p + 3Hp3H5 cmn3HeAcrylic vessel (AV) 12 m diameter1700 tonnes H2O inner shielding1000 tonnes D2O($300 million)5300 tonnes H2O outer shielding~9500 PMT’sCreighton mineSudbury, CA The Sudbury Neutrino Observatory: SNO6800 feet (~2km) underground The heavy water has recently been returned and development work is in progresson SNO+ with liquid scintillator and 150Nd additive.- Entire detectorBuilt as a Class 2000Clean room- Low RadioactivityDetector materialsSNO: One million pieces transported down in the 9 ft x 12 ft x 9 ft mine cage and re-assembled under ultra-clean conditions. Every worker takes a showerand wears clean, lint-free clothing. Over 70,000Showersto date andcountingChristian Nally Jaret HeiseUBC Graduate Students during Detector ConstructionPlease pass on my best wishes to Erich.  He was a strong supporter of graduate students especially myself (well, in my mind) during his tenure as Director of TRIUMF.  It has special meaning for me that the seminar to honour him is in Hebb Theater at UBC.  The first lecture of my first day at university 28 years ago  (sigh) was in Hebb Theater and the professor was Erich Vogt.  I recall apples levitating into the rafters...  - FraserFraser Duncan:- Detector Operations Manager for SNO- Deputy Director of SNO- Associate Director of SNOLABTwo Undergrads taught by Erich Vogt in their first year at UBC:Aksel Hallin:- Tier 1 Canada Research Chair at Alberta- Calibration Group Leader on SNOI came to UBC in 1973 and took the first year honours physics course from Erich. I remember him as someone who was very approachable and really enjoyed students. I also remember talking with Erich before deciding to go to Princeton (his alma mater) for graduate work…. - Aksel- Major work by Chris Waltham and his students on the development and testing of the light collectors installed on each photomultiplier.- Alan Poon with testing apparatus in 1990 at UBC. Did his Ph. D. work on the (p,t) calibration source and is now the Analysis Coordinator for SNO as a Staff Member at LBL.Rich Helmer and TRIUMF staff and students did primary electronics testing and commissioning as well as providing major components for the SNO detector. Rich was the Commissioning Manager.Glove Box and manipulator system for calibration sources“Whiffletrees” for load balancing on ropes supporting the acrylic vesselRoland Roper, Ivor Yhap, Roland Kokke…β’s from 8Li  (Rich Helmer)γ’s  from 16N and t(p,γ)4He (Alan Poon)252Cf neutrons6.13 MeV19.8 MeVEnergy calibrated to ~1.5 %Throughout detector volumeOptical calibration at 5 wavelengths with the “Laserball”SNO Energy Calibrations: 25% of running time+ AmBe, 24Na)syst.()stat.(  35.2)syst.()stat.(  94.4)syst.()stat.(−+−+−+−+−+−===ESNCCCφφφ)scm10 of units(In 126 −−029.0031.0)stat.(023.034.0+−±=NCCCφφElectron neutrinosνμ ,ντThe Total Flux of ActiveNeutrinos is measuredindependently (NC) and agreeswell with solar modelCalculations:5.82 +- 1.3 (Bahcall et al),5.31 +- 0.6 (Turck-Chieze et al)CC, NC FLUXESMEASUREDINDEPENDENTLYFlavor changedetermined by > 7 σ.Electron neutrinos areOnly about 1/3 of total!ijijijijiiiτττμμμeeelisandcwhereeecssciδecssccsscUUUUUUUUUUθθδααsin,cos0000001001000001000100001100002/2/13131313232323231212121232132132132==⎟⎟⎟⎠⎞⎜⎜⎜⎝⎛⋅⎟⎟⎟⎠⎞⎜⎜⎜⎝⎛−⋅⎟⎟⎟⎠⎞⎜⎜⎜⎝⎛−⋅⎟⎟⎟⎠⎞⎜⎜⎜⎝⎛−⋅⎟⎟⎟⎠⎞⎜⎜⎜⎝⎛−=⎟⎟⎟⎠⎞⎜⎜⎜⎝⎛=+−−ilil U νν ∑=If neutrinos have mass:)ELΔm.(θ)νP(ν eμ222 271sin2sin=→For 3 Active neutrinos. (MiniBoone has recently ruled out LSND result)Solar,Reactor AtmosphericFor two neutrino oscillation in a vacuum: (a valid approximation in many cases)Using the oscillation framework:CP Violating Phase Reactor, Accel. Majorana PhasesRange defined for Δm12, Δm23Maki-Nakagawa-Sakata-Pontecorvo matrix(Double β decay only)???Matter Effects – the MSW effect⎥⎦⎤⎢⎣⎡=⎥⎦⎤⎢⎣⎡xexe Hdtdi νννν⎥⎥⎥⎥⎦⎤⎢⎢⎢⎢⎣⎡ +−=cos2θ4EΔmsin2θ4EΔmsin2θ4EΔmNG2cos2θ4EΔmH 222eF222222/22sin)2cos(2sin2sinmENG eFmΔ−=+−=ωθθωθθThe extra term arises because solar νe have an extra interactionvia W exchange with electrons in the Sun or Earth.In the oscillation formula:(Mikheyev, Smirnov, Wolfenstein)MSW effect can produce an energy spectrum distortion and flavor regeneration in Earth giving a Day-night effect.If observed, matter interactions define the mass heirarchy.- The solarresults define themass hierarchy(m2 > m1) through theMatter interaction (MSW)- SNO: CC/NC fluxdefines tan2 θ12 < 1 (ie Non - Maximal mixing)by more than 5standard deviationsSOLAR ONLYAFTER SNO SALTDATASOLAR PLUSKAMLAND (Reactor ν’s) MSW: Large Mixing Angle (LMA) RegionLMA for solar ν predicts very smallspectral distortion, small (~ 3 %) day-nightasymmetry, as observed by SK, SNO040.0037.0Asym OD salt 2 ±=+(Scott Oser and students)Periodicity in Solar Flux?Unbinned Maximum Likelihood Method compares fit forSinusoidal variation with Expectation for zero amplitude. Monte Carlo used to estimate sensitivity shows35% probability of a largerlikelihood ratio (S) with zerosinusoidal amplitude than themaximum S observed in the fits.Conclusion: No observedsinusoidal variation at periodsfrom 1 day to 10 years.Analysis sensitive to amplitudeof 8-10% at 99% C.L..SNO data 1999-2003hep-ex/0507079(Scott Oser and students)SNO Muon & Atmospheric Neutrino AnalysisAnalysis: Chris Waltham,Thomas Kutter,Tyron Tsui,Christian Nally ….Also: Supernova Watch (SNEWS) (Jaret Heise UBC Thesis)SNEWS: International collaboration of detectors to watch for burst of neutrinos from a galactic supernova and alert the astronomical community.Final Phase: SNO Phase III• Search for spectral distortion• Improve solar neutrino flux by breaking the CC and NC correlation (ρ = -0.53 in Phase II):CC: Cherenkov Signal ⇒ PMT ArrayNC: n+3He ⇒ NCD Array• Improvement in θ12, as Neutral-Current Detectors (NCD): An array of 3He proportional counters40 strings on 1-m grid~440 m total active lengthPhase III production data taking Dec 2004 to Dec 2006. D2O now removed. Correlations D2O unconstrained D2O constrained Salt unconstrained NCDNC,CC -0.950 -0.520 -0.521 ~0CC,ES -0.208 -0.162 -0.156 ~-0.2ES,NC -0.297 -0.105 -0.064 ~0BlindAnalysisAnother analysis is almost complete that combines data fromthe first two SNO Phases and reduces the threshold by ~ 1 MeV.This also provides improved accuracy on CC/NC flux ratio and thereforeθ12 mixing matrix element.Blind DataVery low Background. About one count per 2 hours in region of interest. Can be reduced by a factor of more than 20 by pulse shape discrimination.NCD Phase Signal Extraction: Jamieson, Oser…New International Underground Facility: SNOLABPhase 1 Experimental area: Available 2008Cryopit addition: Excavation nearly completed. Available 2009.Total additional excavated volume in new lab: 2 times SNO volume.For Experiments that benefit from a very deep and clean lab:• ν - less Double Beta Decay• Dark Matter• Solar Neutrinos• Geo – neutrinos• Supernova ν `sSUSELDavid Sinclair: Directorof Facility DevelopmentTRIUMF Research Scientist at CarletonSNOLAB  (Same depth as SNO: 2 km)Personnel facilitiesSNO Cavern(Existing)Ladder Labs(2008)Cube Hall (2008)Phase IICryopit (2009)UtilityAreaAll Lab Air: Class < 200070 to 800 times lowerμ fluxes than Gran Sasso, Kamioka.Excavation StatusCryopit Rock RemovalCompleteBolting, Shotcrete andConcrete will be completedn several weeks.Cube Hall and Ladder LabExcavation complete, walls painted, services being installed.Cube HallLadder LabCryopitCube HallLetters of Intent/Interest for SNOLABDark Matter:Timing of Liquid Argon/Neon Scintillation: DEAP-1 (7 kg), MINI-CLEAN (360 kg), DEAP/CLEAN (3.6 Tonne)Freon Super-saturated Gel: PICASSOSilicon Bolometers: SUPER-CDMS (25 kg)Neutrino-less Double Beta Decay:150Nd: Organo-metallic in liquid scintillator in SNO+136Xe: EXO (Gas or Liquid) (Longer Term)CdTe: COBRA (Longer Term)Solar Neutrinos:Liquid Scintillator: SNO+ (also Reactor Neutrinos, Geo-neutrinos) Liquid Ne: CLEAN (also Dark Matter) (Longer Term)SuperNovae:SNO+: Liquid scintillator;    HALO: Pb plus SNO 3He detectors. 6 th Workshop and Experiment Review CommitteeAug 22, 23, 2007www.snolab.caRED IMPLIES APPROVEDFOR SITINGComposition of the Universe as we understand it in 2008(Very different than 20 years ago thanks to very sensitive astronomical, astrophysical and particle physics experiments.)With SNOLAB we can look for Dark Matter particles (WIMPS) left from the Big Bang, with ultra-low radioactive background. NeutrinosAre only a few %Responsible for accelerating the Universe’s expansionDEAP/CLEAN: 1 TonneFiducial Liquid Argon Dark Matter (WIMP) detector  promptF0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1Events/0.01 wide bin11021031041051061071081010 keV  events-enuclear recoilsFrom simulation,γ rejection > 108@ 10 keV108 simulated e-’s100 simulatedWIMPsM.G. Boulay & A. Hime, astro-ph/0411358 (ns)photonT-110 1 10 210 310 410Relative probability-410-310-210-110110electronsnuclear recoils- Scintillation time spectrum for Arenables nuclear recoils from WIMP collisions to be separated from betas and gammas from 39Ar background using only scintillation light.- DEAP and CLEAN collaborationshave come together to build newdetectors with a simple and easily scaled technology at SNOLAB.Queen’s, Alberta, Carleton, Laurentian,SNOLAB, TRIUMF (Retiere), LANL, Yale, Boston, South Dakota, New Mexico, TUNL, Texas, NIST Boulder Cube HallMiniCLEAN360 kg2009DEAP/CLEAN3.6 tonne2010AssemblyClean RoomDEAP/CLEANProcess SystemsDEAP-1 (7 kg): 6 x 10-8 discrimination of 39Ar betas demonstrated in running on surface.Now counting underground. Aiming at  better than 10-9 with lower background there.Existing discrimination would be adequate if depleted argon (x20) from helium sources is used.WIMP Sensitivity with 1 tonne of argon)2malized per nucleon (cm-4410-4310-4210-4110-4010 thresholdeffT15 keVCDMS-IIXENON-10For nominal threshold of 20 keV visible energy, 1000 kg LAr for 3 years is sensitive to 10-46 cm2. Present schedule: Mini-CLEAN 100 kg Fiducial: 2009, DEAP/CLEAN: 1000 kg Fiducial: starting 2010PresentExperimentalLimitsCDMS-2008mνββ(eV)Lightest neutrino (m1) in eVnormal hierarchy inverted hierarchyMeasuring Effective νMass: mνββ = |∑i Uei ² mi |mνββ =  |m1 cos2θ13cos²θ12 + m2 e2iα cos2θ13sin²θ12 + m3 e2iβ sin²θ13|Next Generation Detectors:Want sensitivity <~ 0.04 eVlarge mass/low backgroundInvertedNormalPresent Expts.0.04 eVMass HierarchiesNormal InvertedINTERESTING FOR LEPTOGENESIS(Origin: Matter/Anti-Matter Asymmetry)DegenerateNEUTRINOLESS DOUBLE BETA DECAY: SNO+ (150Nd), EXO (136Nd)Neutrinos must be Majorana particlesAV Hold DownRopes(V. Strickland, TRIUMF Carleton:Finite element calcs.) ExistingAV SupportRopesThe organicliquid is lighterthan water sothe Acrylic Vesselmust be held down.Main Engineering Changes for SNO+ : Scint. Purification, AV Hold DownOtherwise, the existing detector, electronics etc. are unchanged.• Nd is one of the most favorable double beta decay candidates with large phase space due to high endpoint: 3.37 MeV.• Ideal scintillator (Linear Alkyl Benzene) has been identified. More light output than Kamland, Borexino, no effect on acrylic.• Nd metallic-organic compound has been demonstrated to have long attenuation lengths, stable for more than a year. • 1 tonne of Nd will cause very little degradation of light output.• Isotopic abundance 5.6% (in SNO+ 1 tonne Nd = 56 kg 150Nd) • Collaboration to enrich 150Nd using French laser isotope facility.  Possibility of hundreds of kg of isotope production.• SNO+ Capital proposal to be submitted Oct. 2008. • Plan to start with natural Nd in 2010.• Other physics: CNO solar neutrinos, pep solar neutrinos to study neutrino properties, geo-neutrinos, supernova search.. SNO+: Neutrino-less Double Beta Decay: 150NdQueen’s, Alberta, Laurentian, SNOLAB, BNL, Washington, Penn, Texas, LIP Lisbon, Oxford, Sussex, Dresden0ν: 1057 events peryear with 500 kg150Nd-loaded liquidscintillator in SNO+.Simulationassuming lightoutput and backgroundsimilar to Kamland.SNO+ (150Nd ν - less Double Beta Decay)One year of datamν= 0.15 eVSensitivity (3 yrs): Natural Nd (56 kg isotope):  mνββ ~ 0.1 eV500 kg enriched 150Nd: mνββ ~ 0.03 eVU Chain Th ChainH eliumA ndL eadO bservatoryA lead detector forsupernova neutrinosin SNOLABLaurentian, TRIUMF (Yen), SNOLAB, LANL, Washington, Duke, Minnesota, Digipen IT HALO-1: 80 tons of existing Pb& SNO Neutron Detector Array Pb: Most sensitivity to electron neutrinos.~ 50 events for SN at center of Galaxy.Anode PadsMicro-megasWLS BarElectrode Xe GasIsobutaneTEA.  .  .  .  .  .  .  ..  .  .  .  .  .  .  .For 200 kg, 10 bar, box is 1.5 m on a sidePMTLasersGridsBa IonElectronsR&D in Canada: EXO-gas double beta counter136Xe decayEXO-gas Canada: Carleton (Sinclair), LaurentianMontreal, Queen’sIndiana, Pisa, BTIFluorine is very sensitive for the spin-dependent interactionWIMP-Nucleus Spin-Dependent InteractionAcousticSignalUp to 2.6 kg being run in 2007-08SummaryExcellent Partnerships in the past and for the future….All of us in Canadian Subatomic physics owe atremendous amount to:Erich W. VogtTRIUMF Director 1981-94Canadian Statesmanin Sub-atomic Physics


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