Vogt Symposium

TRIUMF and UBC in the SNO Experiment 2008

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Erich W. Vogt Canadian Statesman in Sub-atomic Physics TRIUMF and UBC in the SNO Project Faculty, and TRIUMF Scientists: Chris Waltham, Rich Helmer, Scott Oser Post Docs: Salvador Gil, Rob Komar , Thomas Kutter, Juergen Wendland, Blair Jamieson, Ron Schubank, Reena Meijer Drees Graduate Students: Alan Poon, Jaret Heise, Christian Nally, Tyron Tsui, Louis McGarry, Guy Ouellette Undergraduates: Mitch Crowe, Bryce Croll, Ben Short, Ivan Sham, Jamil Sharif, Tudor Costin, Dave Branch, Jonathan Harris, Rob Newman, Vicky Valiani, Kiara Moran, Siong Ng, Chris Nell, Chris Callendar, Sam Marchand, Janice Boyce Bahcall et al. , SNO Flavour Change for Solar Neutrinos Solar Model Flux Calculations CNO SNO was designed to observe separately νe and all neutrino types to determine if low νe fluxes come from flavor change or solar models Previous Experiments Sensitive to Electron Neutrinos Unique Signatures in SNO (D2O) Charged-Current (CC) νe+d → e-+p+p Ethresh = 1.4 MeV νe only Elastic Scattering (ES) (D2O & H2O) νx+e- → νx+e- νx, but enhanced for νe Neutral-Current (NC) νx+d → νx+n+p Ethresh = 2.2 MeV Equally sensitive to νe νμ ντ 3 ways to detect neutrons Phase II (salt) July 01 - Sep. 03 Phase III (3He) Nov. 04-Dec. 06 Phase I (D2O) Nov. 99 - May 01 SNO: 3 neutron (NC) detection methods (systematically different) n captures on 2H(n, γ)3H Effc. ~14.4% NC and CC separation by energy, radial, and directional distributions 40 proportional counters 3He(n, p)3H Effc. ~ 30% capture Measure NC rate with entirely different detection system. 2 t NaCl. n captures on 35Cl(n, γ)36Cl Effc. ~40% NC and CC separation by event isotropy 36Cl 35Cl+n 8.6 MeV 3H 2H+n 6.25 MeV n + 3He → p + 3H p 3H 5 cm n 3He Acrylic vessel (AV) 12 m diameter 1700 tonnes H2O inner shielding 1000 tonnes D2O ($300 million) 5300 tonnes H2O outer shielding ~9500 PMT’s Creighton mine Sudbury, CA The Sudbury Neutrino Observatory: SNO 6800 feet (~2km) underground The heavy water has recently been returned and development work is in progress on SNO+ with liquid scintillator and 150Nd additive. - Entire detector Built as a Class 2000 Clean room - Low Radioactivity Detector materials SNO: 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 shower and wears clean, lint-free clothing. Over 70,000 Showers to date and counting Christian Nally Jaret Heise UBC Graduate Students during Detector Construction Please 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...  - Fraser Fraser Duncan: - Detector Operations Manager for SNO - Deputy Director of SNO - Associate Director of SNOLAB Two Undergrads taught by Erich Vogt in their first year at UBC: Aksel Hallin: - Tier 1 Canada Research Chair at Alberta - Calibration Group Leader on SNO I 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 neutrons 6.13 MeV 19.8 MeV Energy calibrated to ~1.5 % Throughout detector volume Optical 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.(  68.1 15.0 15.0 22.0 22.0 38.0 34.0 21.0 21.0 08.0 09.0 06.0 06.0 + − + − + − + − + − + − = = = ES NC CC φ φ φ )scm10 of units(In 126 −− 029.0 031.0)stat.(023.034.0 + −±= NC CC φ φ Electron neutrinos νμ , ντ The Total Flux of Active Neutrinos is measured independently (NC) and agrees well with solar model Calculations: 5.82 +- 1.3 (Bahcall et al), 5.31 +- 0.6 (Turck-Chieze et al) CC, NC FLUXES MEASURED INDEPENDENTLY Flavor change determined by > 7 σ. Electron neutrinos are Only about 1/3 of total! ijijijij ii i τττ μμμ eee li sandcwhere e e cs sc iδecs sccs sc UUU UUU UUU U θθ δα α sin,cos 00 00 001 0 010 0 00 010 001 0 0 001 100 0 0 2/ 2/ 1313 1313 2323 23231212 1212 321 321 321 3 2 == ⎟⎟ ⎟ ⎠ ⎞ ⎜⎜ ⎜ ⎝ ⎛ ⋅ ⎟⎟ ⎟ ⎠ ⎞ ⎜⎜ ⎜ ⎝ ⎛ − ⋅ ⎟⎟ ⎟ ⎠ ⎞ ⎜⎜ ⎜ ⎝ ⎛ − ⋅ ⎟⎟ ⎟ ⎠ ⎞ ⎜⎜ ⎜ ⎝ ⎛ − ⋅ ⎟⎟ ⎟ ⎠ ⎞ ⎜⎜ ⎜ ⎝ ⎛ −= ⎟⎟ ⎟ ⎠ ⎞ ⎜⎜ ⎜ ⎝ ⎛ = +− − ilil U νν ∑=If neutrinos have mass: ) E LΔm.(θ)νP(ν eμ 2 22 271sin2sin=→ For 3 Active neutrinos. (MiniBoone has recently ruled out LSND result) Solar,Reactor Atmospheric For two neutrino oscillation in a vacuum: (a valid approximation in many cases) Using the oscillation framework: CP Violating Phase Reactor, Accel. Majorana Phases Range defined for Δm12, Δm23 Maki-Nakagawa-Sakata-Pontecorvo matrix (Double β decay only)? ? ? Matter Effects – the MSW effect ⎥⎦ ⎤⎢⎣ ⎡=⎥⎦ ⎤⎢⎣ ⎡ x e x e H dt di ν ν ν ν ⎥⎥ ⎥⎥ ⎦ ⎤ ⎢⎢ ⎢⎢ ⎣ ⎡ +− = cos2θ 4E Δmsin2θ 4E Δm sin2θ 4E ΔmNG2cos2θ 4E Δm H 22 2 eF 2 2 22 2 2 /2 2sin)2cos( 2sin2sin mENG eF m Δ−= +−= ω θθω θθ The extra term arises because solar νe have an extra interaction via 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 solar results define the mass hierarchy (m2 > m1) through the Matter interaction (MSW) - SNO: CC/NC flux defines tan2 θ12 < 1 (ie Non - Maximal mixing) by more than 5 standard deviations SOLAR ONLY AFTER SNO SALT DATA SOLAR PLUS KAMLAND (Reactor ν’s) MSW: Large Mixing Angle (LMA) Region LMA for solar ν predicts very small spectral distortion, small (~ 3 %) day-night asymmetry, as observed by SK, SNO 040.0037.0Asym OD salt 2 ±=+ (Scott Oser and students) Periodicity in Solar Flux? Unbinned Maximum Likelihood Method compares fit for Sinusoidal variation with Expectation for zero amplitude. Monte Carlo used to estimate sensitivity shows 35% probability of a larger likelihood ratio (S) with zero sinusoidal amplitude than the maximum S observed in the fits. Conclusion: No observed sinusoidal variation at periods from 1 day to 10 years. Analysis sensitive to amplitude of 8-10% at 99% C.L.. SNO data 1999-2003 hep-ex/0507079 (Scott Oser and students) SNO Muon & Atmospheric Neutrino Analysis Analysis: 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 Array NC: n+3He ⇒ NCD Array • Improvement in θ12, as Neutral-Current Detectors (NCD): An array of 3He proportional counters 40 strings on 1-m grid ~440 m total active length Phase III production data taking Dec 2004 to Dec 2006. D2O now removed. Correlations D2O unconstrained D2O constrained Salt unconstrained NCD NC,CC -0.950 -0.520 -0.521 ~0 CC,ES -0.208 -0.162 -0.156 ~-0.2 ES,NC -0.297 -0.105 -0.064 ~0 Blind Analysis Another analysis is almost complete that combines data from the first two SNO Phases and reduces the threshold by ~ 1 MeV. This also provides improved accuracy on CC/NC flux ratio and therefore θ12 mixing matrix element. Blind Data Very 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: SNOLAB Phase 1 Experimental area: Available 2008 Cryopit 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 `s SUSEL David Sinclair: Director of Facility Development TRIUMF Research Scientist at Carleton SNOLAB  (Same depth as SNO: 2 km) Personnel facilitiesSNO Cavern (Existing) Ladder Labs (2008) Cube Hall (2008) Phase II Cryopit (2009) Utility Area All Lab Air: Class < 2000 70 to 800 times lower μ fluxes than Gran Sasso, Kamioka. Excavation Status Cryopit Rock Removal Complete Bolting, Shotcrete and Concrete will be completed n several weeks. Cube Hall and Ladder Lab Excavation complete, walls painted, services being installed. Cube Hall Ladder Lab Cryopit Cube Hall Letters of Intent/Interest for SNOLAB Dark Matter: Timing of Liquid Argon/Neon Scintillation: DEAP-1 (7 kg), MINI-CLEAN (360 kg), DEAP/CLEAN (3.6 Tonne) Freon Super-saturated Gel: PICASSO Silicon 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 Committee Aug 22, 23, 2007 www.snolab.ca RED IMPLIES APPROVED FOR SITING Composition 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. Neutrinos Are only a few % Responsible for accelerating the Universe’s expansion DEAP/CLEAN: 1 Tonne Fiducial Liquid Argon Dark Matter (WIMP) detector promptF 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 E v e n t s / 0 . 0 1  w i d e  b i n 1 10 210 310 410 510 610 710 810 10 keV  events -e nuclear recoils From simulation, γ rejection > 108 @ 10 keV 108 simulated e-’s 100 simulated WIMPs M.G. Boulay & A. Hime, astro-ph/0411358  (ns)photonT -110 1 10 210 310 410 R e l a t i v e  p r o b a b i l i t y -410 -310 -210 -110 1 10 electrons nuclear recoils - Scintillation time spectrum for Ar enables nuclear recoils from WIMP collisions to be separated from betas and gammas from 39Ar background using only scintillation light. - DEAP and CLEAN collaborations have come together to build new detectors 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 Hall MiniCLEAN 360 kg 2009 DEAP/CLEAN 3.6 tonne 2010 Assembly Clean Room DEAP/CLEAN Process Systems DEAP-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 ) 2 m a l i z e d  p e r  n u c l e o n  ( c m -4410 -4310 -4210 -4110 -4010  thresholdeffT 15 keV CDMS-II XENON-10 For 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 2010 Present Experimental Limits CDMS-2008 mν β β ( e V ) Lightest neutrino (m1) in eV normal hierarchy inverted hierarchy Measuring Effective ν Mass: mνββ = |∑i Uei ² mi | mνββ =  |m1 cos2θ13cos²θ12 + m2 e2iα cos2θ13sin²θ12 + m3 e2iβ sin²θ13| Next Generation Detectors: Want sensitivity <~ 0.04 eV large mass/low background Inverted Normal Present Expts. 0.04 eV Mass Hierarchies Normal Inverted INTERESTING FOR LEPTOGENESIS (Origin: Matter/Anti-Matter Asymmetry) Degenerate NEUTRINOLESS DOUBLE BETA DECAY: SNO+ (150Nd), EXO (136Nd) Neutrinos must be Majorana particles AV Hold Down Ropes (V. Strickland, TRIUMF Carleton: Finite element calcs.) Existing AV Support Ropes The organic liquid is lighter than water so the Acrylic Vessel must be held down. Main Engineering Changes for SNO+ : Scint. Purification, AV Hold Down Otherwise, 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: 150Nd Queen’s, Alberta, Laurentian, SNOLAB, BNL, Washington, Penn, Texas, LIP Lisbon, Oxford, Sussex, Dresden 0ν: 1057 events per year with 500 kg 150Nd-loaded liquid scintillator in SNO+. Simulation assuming light output and background similar to Kamland. SNO+ (150Nd ν - less Double Beta Decay) One year of data mν = 0.15 eV Sensitivity (3 yrs): Natural Nd (56 kg isotope):  mνββ ~ 0.1 eV 500 kg enriched 150Nd: mνββ ~ 0.03 eV U Chain Th Chain H elium A nd L ead O bservatory A lead detector for supernova neutrinos in SNOLAB Laurentian, 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 Pads Micro-megas WLS Bar Electrode Xe Gas Isobutane TEA .  .  .  .  .  .  .  . .  .  .  .  .  .  .  . For 200 kg, 10 bar, box is 1.5 m on a side PMT Lasers Grids Ba Ion Electrons R&D in Canada: EXO-gas double beta counter 136Xe decay EXO-gas Canada: Carleton (Sinclair), Laurentian Montreal, Queen’s Indiana, Pisa, BTI Fluorine is very sensitive for the spin-dependent interaction WIMP-Nucleus Spin-Dependent Interaction Acoustic Signal Up to 2.6 kg being run in 2007-08 Summary Excellent Partnerships in the past and for the future…. All of us in Canadian Subatomic physics owe a tremendous amount to: Erich W. Vogt TRIUMF Director 1981-94 Canadian Statesman in Sub-atomic Physics 


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