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DARK 2007 Sydney Sept 28th,2007 Page 1
Knowing the Universe from a Hole in the Ground
Particle-Astrophysics Researchat
SNO & SNOLab
T. Noble, Queen’s UniversityThe Past
The Sudbury Neutrino Observatory ( SNO )
• Current Status
The Future
SNOLab
• Physics potential
• Status
DARK 2007 Sydney Sept 28th,2007 Page 2
SNO
Status• Data acquisition, NCD phase, complete November 28,
2006• Heavy water returned by May, 2007• Analysis proceeding well. • Primary focus:
– NC and CC data from NCD Phase.– Low Energy Threshold Analysis (LETA) from previous phases.
• Analysis will continue until April 2009
Main Results:
•30 year old Solar Neutrino Puzzle solved… •Strong evidence for weak flavor change (> 7 sigma). Solar Neutrino Oscillations! Neutrinos have finite mass, mix…•Total Flux in excellent agreement with expectations from solar
models We have a good understanding of the fusion processes in the
Sun…
DARK 2007 Sydney Sept 28th,2007 Page 3
Getting The Last Drop Out!
DARK 2007 Sydney Sept 28th,2007 Page 4
SNO data taking is Complete.
The Experiment is Decommissioned.
What is the future programme for Particle Astrophysics at this Facility?
DARK 2007 Sydney Sept 28th,2007 Page 5
SNOLAB
A new International Facility for Underground Science.
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Physics Program• Direct Search for Dark Matter 85% of mass in universe + MSSM DEAP/CLEAN, PICASSO,
SuperCDMS MiniClean?, LUX?• Neutrino Properties
– Neutrinoless double beta decay Majorana, mass scale, hierarchy EXO, SNO+
– Solar neutrinos mixing parameters, solar/stellar– Supernova neutrinos physics, new physics– Reactor neutrinos SNO+, HALO ?
• Geophysics– Geo-neutrinos Earth’s heat flow SNO+– Seismology seismic wave propagation
PUPS• Biology
~25 letters of interest received…Initial suite of experiments recommended by an International Experiment Advisory Committee.
DARK 2007 Sydney Sept 28th,2007 Page 7
What is required to advance these areas of science?
• All require very low background environment– Implies deep site– Clean lab
• Some projects require big detector so some spaces must be large
• Many projects use noble liquids or gases which raise safety concerns, and require a dedicated and isolated space.
DARK 2007 Sydney Sept 28th,2007 Page 8
The Requirement for SNOLAB depth
Phys.Rev. D73 (2006) 053004
Mei, D.M. and Hime, A.
•SNOLAB depth allows 10-47 cm2 cross-section sensitivity for dark matter
•Simplest experiment is with passive shielding afforded by rock at deep site
DARK 2007 Sydney Sept 28th,2007 Page 9
SNO: The Sudbury Neutrino Observatory
DARK 2007 Sydney Sept 28th,2007 Page 10
ExistingSNO Facility
SNOLAB
SNOLAB Workshop 22-23 August 2007
DARK 2007 Sydney Sept 28th,2007 Page 11
ExistingSNO Facility
Phase I
Relocate-Lab Entry-Personnel Facilities
UtilityArea- Chiller- Generator
SNOLAB
SNOLAB Workshop 22-23 August 2007
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ExistingSNO Facility
Phase I
Relocate-Lab Entry-Personnel Facilities
UtilityArea- Chiller- Generator
Phase II
SNOLAB
SNOLAB Workshop 22-23 August 2007
* Excavation began Fall 2004, completed May 2007* Outfitting began June 2007
* Funding announced August 07* Construction began June 07
DARK 2007 Sydney Sept 28th,2007 Page 13
SNOLAB Underground facilities
SNO
Rectangular Hall
LadderUtilities
DARK 2007 Sydney Sept 28th,2007 Page 14
Excavation Clean Rm LaboratoryArea Volume Area Volume Area Volume
Existing
Existing+ Phase I
Existing
+ Phase I &I I
20,049 f t2 582,993 f t3 12,196 f t2 470,360 f t3 8,095 f t2 412,390 f t3
1,863 m2 16,511 m3 1,133 m2 13,321 m3 752 m2 11,679 m3
65,340 f t2 1,367,488 f t3 41,955 f t2 1,049,393 f t3 26,117 f t2 837,604 f t3
6,072 m2 38,728 m3 3,899 m2 29,719 m3 2,427 m2 23,721 m3
77,636 f t2 1,647,134 f t3 53,180 f t2 1,314,973 f t3 32,877 f t2 1,043,579 f t3
7,215 m2 46,648 m3 4,942 m2 37,241 m3 3,055 m2 29,555 m3
Laboratory Space
SNOLAB Workshop 22-23 August 2007
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0υββ at SNOLAB
SNO+ & EXOgas
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SNO+ (SNO with Liquid Scintillator)• heavy water is returned• replace with liquid scintillator and use existing SNO apparatus• Inexpensive, could be collecting data soon!
What can be measured?• low energy solar neutrinos - pep, CNO, 7Be• geo-neutrinos - anti-neutrinos from U/Th• reactor neutrinos - Bruce and Darlington• live for supernova • potential for large mass 0υbb decay experiment with 150Nd
What are the challenges?- some re-engineering of experiment- purification of scintillator
DARK 2007 Sydney Sept 28th,2007 Page 17
150Nd Option
• 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 !!
• Isotopic Enrichment:– 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
DARK 2007 Sydney Sept 28th,2007 Page 18
0: 1000 events per year with 1% natural Nd-loaded liquid scintillator in SNO+
Poor energy resolution compensated by high statistics
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
DARK 2007 Sydney Sept 28th,2007 Page 19
SNO+ Double Beta Spectrum
1 yr, 500 kg isotope, m = 150 meV
DARK 2007 Sydney Sept 28th,2007 Page 20
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)
DARK 2007 Sydney Sept 28th,2007 Page 21
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+
DARK 2007 Sydney Sept 28th,2007 Page 22
XeXe off ers a qualitatively new tool against background:off ers a qualitatively new tool against background:136136Xe Xe 136136BaBa++++ee-- ee-- final state can be identified final state can be identified
using optical spectroscopy using optical spectroscopy ((M.MoeM.Moe PRC44 (1991) 931)PRC44 (1991) 931)
BaBa++ system best studiedsystem best studied((NeuhauserNeuhauser, , HohenstattHohenstatt,,ToshekToshek, , DehmeltDehmelt 1980)1980)Very specific signatureVery specific signature
““shelvingshelving””Single ions can be detectedSingle ions can be detectedfrom a photon rate of 10from a photon rate of 1077/s/s
••Important additionalImportant additionalconstraintconstraint
••Huge backgroundHuge backgroundreductionreduction
22PP1/21/2
44DD3/23/2
22SS1/21/2
493nm493nm
650nm650nm
metastablemetastable 80s80s
Farther in the future:
EXO GAS: 200 Kg Xe TPC with Barium tagging technique
DARK 2007 Sydney Sept 28th,2007 Page 23
Dark Matter at SNOLAB
DEAP/Clean, MiniClean, PICASSO
&
SuperCDMS
DARK 2007 Sydney Sept 28th,2007 Page 24
DEAP/CLEAN
Liquid Argon
Pulse Shape Discrimination of Scintillation light
1000 Kg Fiducial
Spin-Independent
DARK 2007 Sydney Sept 28th,2007 Page 25
Why Argon and Pulse Shape Discrimination?
Highly sensitive and inexpensive technique to scale up to tonne scales.
DARK 2007 Sydney Sept 28th,2007 Page 26
DARK 2007 Sydney Sept 28th,2007 Page 27
Deap/CLEAN Physics potential
DARK 2007 Sydney Sept 28th,2007 Page 28
Picasso Superheated Droplet Detector
• Detector consists of tiny (5 to 100 m) halocarbon liquid droplets (C4F10) embedded in a gel.
• The droplets are superheated - maintained at a temperature higher than their boiling point.
DARK 2007 Sydney Sept 28th,2007 Page 29
•When a nuclear recoil (from WIMP, or neutron interaction, or alpha) deposits a spike of heat into droplet, it rapidly evaporates.
•The evaporating bubble creates a sound shock wave, which can be recorded by a sensitive microphone.
Detector Operation
A bubble forms iff the particle creates a heat spike
• with enough energy Emin
• deposited within Rmin
Mainly sensitive to heavily ionizing particles
DARK 2007 Sydney Sept 28th,2007 Page 30
Sensitivity:
Operate over this temperature range
Insensitive to MIPS, β, γ
DARK 2007 Sydney Sept 28th,2007 Page 31
SNOLAB
Status and Schedule
DARK 2007 Sydney Sept 28th,2007 Page 32
SNO Cavern:2008: SNO+
SNO Utility Rm:PICASSO-IB (2kg)
Ladder Labs: 2 of2009: PICASSO IIB2009: EXO-200-Gas2009: Majorana (TBD)2010: CDMS
SNO Control Rm:2007: DEAP-1
Cube Hall: 1 of2008: DEAP/CLEAN2009: PICASSO-III2009: LUX
Cryopit: 1 of2008: DEAP/CLEAN2009: LUX2015?: EXO2015?: 1T GERDA2015?: CLEAN-100T
2008:HALO
DARK 2007 Sydney Sept 28th,2007 Page 33
• Phase I (Cube Hall, Ladder Labs)
– Excavation 100% complete.
– Outfitting began June 2007, complete early 2008.
• Phase II (Cryopit)
– Funding announced Aug 2007.
– Excavation had started in anticipation and will be in parallel with outfitting of Phase I.
– Ready for occupancy mid 2008.
• Surface Facility
– Operational since 2005.
• SNOLAB Workshop: Aug 22/23 2007 Sudbury On– Initial assignments of space underground.
– See: www.snolab.ca
SNOLAB Status
DARK 2007 Sydney Sept 28th,2007 Page 34
Excavation Status
DARK 2007 Sydney Sept 28th,2007 Page 35
CUBEHALL
DARK 2007 Sydney Sept 28th,2007 Page 36
CUBEHALL
DARK 2007 Sydney Sept 28th,2007 Page 37
LADDERLABS
DARK 2007 Sydney Sept 28th,2007 Page 38
Shotcrete linear complete: Hand Troweled surface to enhance cleanliness.
SNOLAB Workshop 22-23 August 2007
DARK 2007 Sydney Sept 28th,2007 Page 39
PersonnelArea
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CryopitTop Access
DARK 2007 Sydney Sept 28th,2007 Page 41
Surface Facilities Complete and in use
DARK 2007 Sydney Sept 28th,2007 Page 42
IT Server Room
Control Rooms
Meeting Rooms
Clean Room Laboratories
DARK 2007 Sydney Sept 28th,2007 Page 43
Schedule
Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
SNO Phase III Data Taking
* End of SNO Data Taking
SNO Decommissioning
Complete Excavation Cube Hall and Ladder Labs
Excavation of Cryopit
Outfitting of Entry, Cube Hall, Ladder Labs
Relocation of Lab Entrance
Conversion of old Personnel Facilities
Outfitting of Cryopit, Chiller
* Begin Experiment installation in Cube Hall and Ladder Labs
* South Drift Available
* Cryopit Available
2007 2008 20092006
DARK 2007 Sydney Sept 28th,2007 Page 44
The Bottom Line
– SNOLAB is nearing completion
– All the capital funding for the facility is in place– The operations funding is coming together– Funding for experiments has started to flow
– Exciting experimental program being developed, and on track for start in early 2008.
SNOLAB is Open for Business
DARK 2007 Sydney Sept 28th,2007 Page 45
DARK 2007 Sydney Sept 28th,2007 Page 46
DARK 2007 Sydney Sept 28th,2007 Page 47
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 +
DARK 2007 Sydney Sept 28th,2007 Page 48
Vacuum vs Matter Enhanced Survival Probability
vacuumoscillation
matterenhancedoscillationtr
an
siti
on
reg
ion
solar pp pep 8B
• 3-5% flux measurement
• compare SNO+/SSM
(SSM=1.5%)
• confirm MSW model
• improve 12 precision
• sensitive to new physics
DARK 2007 Sydney Sept 28th,2007 Page 49
• muon rate in KamLAND: 26,000 d−1
• compared with SNO:
70 d−1
these plots from the KamLAND proposal
11C Cosmogenic Background
DARK 2007 Sydney Sept 28th,2007 Page 50
SNO+ AV Hold Down
AV Hold DownRopes
ExistingAV SupportRopes
DARK 2007 Sydney Sept 28th,2007 Page 51
Phase 1a: (published in ’05 PLB, NIM) 20g 2kgdBckg: 480 /kg/d
Phase Ib: (ongoing)2.6 kg 336 kgdBckg: 80/kg/d
Spin Dependent Sector
Phase II:25 kg 3600 kgdBckg: 0.8 /kg/dLadder LabPhase III:100 kg 28000 kgdBckg: 0.08 /kg/d
Picasso phased approach
(Bckg.values: integrated from 6 keV – 1 MeV )
Phase Ia
Phase Ib
Phase II
Phase III
DARK 2007 Sydney Sept 28th,2007 Page 52
A number of extremely fundamental questions can be addressed by the scientific program of SNOLAB:
What is Dark Matter?
Is there a new symmetry of nature (Supersymmetry or …) that will reveal itself at higher energies?
Why is the Universe dominated by matter, and how did this asymmetry come about?
What are the neutrino masses, and how have they contributed to the structure and evolution of the Universe?
How were the heavy elements formed in Supernovae, and what is the role of neutrinos in that process. How do cosmic accelerators work?
What is the mechanism responsible for neutrino oscillations in the sun (MSW matter oscillations or ?)
DARK 2007 Sydney Sept 28th,2007 Page 53
LADDERLABS
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