DARK 2007 SydneySept 28 th,2007Page 1 Knowing the Universe from a Hole in the Ground Particle-Astrophysics Research at SNO & SNOLab T. Noble, Queen’s University

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


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…


Getting The Last Drop Out!


SNO data taking is Complete.

The Experiment is Decommissioned.

What is the future programme for Particle Astrophysics at this Facility?


SNOLAB

A new International Facility for Underground Science.


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.


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.


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


SNO: The Sudbury Neutrino Observatory


ExistingSNO Facility

SNOLAB

SNOLAB Workshop 22-23 August 2007



Phase I

Relocate-Lab Entry-Personnel Facilities

UtilityArea- Chiller- Generator

SNOLAB




Phase I

Relocate-Lab Entry-Personnel Facilities

UtilityArea- Chiller- Generator

Phase II

SNOLAB


* Excavation began Fall 2004, completed May 2007* Outfitting began June 2007

* Funding announced August 07* Construction began June 07


SNOLAB Underground facilities

SNO

Rectangular Hall

LadderUtilities


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



0υββ at SNOLAB

SNO+ & EXOgas


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


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


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


SNO+ Double Beta Spectrum

1 yr, 500 kg isotope, m = 150 meV


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)


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+


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 Matter at SNOLAB

DEAP/Clean, MiniClean, PICASSO

&

SuperCDMS


DEAP/CLEAN

Liquid Argon

Pulse Shape Discrimination of Scintillation light

1000 Kg Fiducial

Spin-Independent


Why Argon and Pulse Shape Discrimination?

Highly sensitive and inexpensive technique to scale up to tonne scales.



Deap/CLEAN Physics potential


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.


•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


Sensitivity:

Operate over this temperature range

Insensitive to MIPS, β, γ


SNOLAB

Status and Schedule


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


• 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


Excavation Status


CUBEHALL


CUBEHALL


LADDERLABS


Shotcrete linear complete: Hand Troweled surface to enhance cleanliness.



PersonnelArea


CryopitTop Access


Surface Facilities Complete and in use


IT Server Room

Control Rooms

Meeting Rooms

Clean Room Laboratories


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


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




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 +


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


• muon rate in KamLAND: 26,000 d−1

• compared with SNO:

70 d−1

these plots from the KamLAND proposal

11C Cosmogenic Background


SNO+ AV Hold Down

AV Hold DownRopes

ExistingAV SupportRopes


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


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 ?)


LADDERLABS

Documents

DARK 2007 SydneySept 28 th,2007Page 1 Knowing the Universe from a Hole in the Ground Particle-Astrophysics Research at SNO & SNOLab T. Noble, Queen’s University