SNO+ Solar Neutrino Program
The SNO+ detector
SNO+ solar neutrino program
Freija Descamps for the SNO+ collaboration
JinPing - SNO+ Solar 1 Freija Descamps, 09/06/2014 SNOLAB and SNO+
✤ SNO+ = successor to Sudbury Neutrino Observatory (SNO) ✤ Located in SNOLAB inside the Creighton mine near Sudbury, Canada ✤ Depth = 2070m (6000m.w.e) ✤ ~70 muons/day in SNO+ ✤ Class-2000 clean room
JinPing - SNO+ Solar 2 Freija Descamps, 09/06/2014 SNOLAB and SNO+
✤ Deck with DAQ SNO+ operator SNO+ = successor to Sudbury Neutrino Observatory (SNO)
✤ ~780T LAB Located in SNOLAB inside the liquid organic Creighton mine near Sudbury, scintillator Canada + PPO ✤ Depth = 2070m (6000m.w.e) ✤ ~70 muons/day in SNO+ acrylic vessel ✤ Class-2000 clean room ⌀ 12m 5cm thick
~9500 PMTs 54% coverage
~7kT ultra- pure water shield
rock
JinPing - SNO+ Solar 2 Freija Descamps, 09/06/2014 Liquid scintillator
✤ LAB: Linear AlkylBenzene ✤ Long attenuation length (~20m) ✤ Safe: low toxicity and high flash point ✤ Chemically compatible with acrylic ✤ α-β separation through scintillation decay-times ✤ High light yield ~10000�/MeV ✤ Fluor: 2.5-Diphenyloxazol (PPO) ✤ 2g/L
Petresa plant Bécancour, QC NIM A640, 119-122 (2011) 3 JinPing - SNO+ Solar Freija Descamps, 09/06/2014 LAB purification plan
Distillation Water extraction
✤ Multi-stage distillation ✤ Removes heavy metals ✤ Improves UV transparency ✤ Dual-stream PPO distillation ✤ N2/steam stripping
✤ Removes Rn, Kr, Ar, O2 ✤ Water extraction ✤ Removes Ra, K, Bi ✤ Metal scavenging ✤ Removes Bi, Pb ✤ Microfiltration ✤ Removes dust
C-200 Water Extraction Column
JinPing - SNO+ Solar 4 Freija Descamps, 09/06/2014 LAB purification plan
Distillation Water extraction
✤ Multi-stage distillation ✤ Removes heavy metals ✤ Improves UV transparency ✤ Dual-stream PPO distillation ✤ N2/steam stripping
✤ Removes Rn, Kr, Ar, O2 ✤ Water extraction ✤ Removes Ra, K, Bi Target levels: ✤ Metal scavenging 85Kr: 10-25 g/g ✤ Removes Bi, Pb 40K: 10-18 g/g ✤ Microfiltration 39Ar: 10-24 g/g ✤ Removes dust U: 10-17 g/g Th: 10-18 g/g C-200 Water Extraction Column
JinPing - SNO+ Solar 4 Freija Descamps, 09/06/2014 SNO+ solar goals
✤ What can neutrinos tell is about the Sun? ✤ CNO flux measurement Resolve solar metallicity ✤ Direct pp measurement Luminosity constraint ! ✤ What can the Sun tell us about neutrinos? ✤ Day/night asymmetry Confirm MSW ✤ Precision pep flux Search for new physics in ✤ 8 Low-energy B spectrum } transition region
JinPing - SNO+ Solar 5 Freija Descamps, 09/06/2014 SNO+ solar goals
✤ What can neutrinos tell is about the Sun? ✤ CNO flux measurement Resolve solar metallicity ✤ Direct pp measurement Luminosity constraint ! ✤ What can the Sun tell us about neutrinos? ✤ Day/night asymmetry Confirm MSW ✤ Precision pep flux Search for new physics in ✤ 8 Low-energy B spectrum } transition region
Non-standard physics effects can Friedland, alter the shape / position of the Lunardini, Peña-Garay, “MSW rise” PLB 594, (2004)
JinPing - SNO+ Solar 5 Freija Descamps, 09/06/2014 Survival probability
Phys. Rev. D 88, 053010 (2013)
JinPing - SNO+ Solar 6 Freija Descamps, 09/06/2014 Solar Neutrinos
First SNO
SNO: LETA
JinPing - SNO+ Solar 7 Freija Descamps, 09/06/2014 Solar Neutrinos
First SNO
SNO: LETA
SNO+
JinPing - SNO+ Solar 8 Freija Descamps, 09/06/2014 Backgrounds
✤ 39 Ar Cosmogenic! ✤ 210Bi e.g. 11C, 10C ✤ 11C ✤ 14C ✤ 40K External AV, PMTs, ✤ 85Kr H2O, ropes ✤ 210Pb
✤ 210Po Internal!
✤ LS, U chain water, AV ✤ Th chain leaching, internal ropes e.g. 14C, 210Bi,
JinPing - SNO+ Solar 9 Freija Descamps, 09/06/2014 U and Th chains
✤ Purification techniques ✤ Direct background α and β emissions ✤ Coincidence techniques are under investigation, ex.: ✤ β-α ⇾ 214Bi-214Po ✤ β-α ⇾ 212Bi-212Po ✤ α-β ⇾ 212Bi-208Tl ✤ 95-99.9% rejection ✤ 50% fiducial volume cut to reject external backgrounds
JinPing - SNO+ Solar 10 Freija Descamps, 09/06/2014 11C background
11C produced by cosmic hitting organic molecules
Analytically generated spectra with 5%/ E resolution 104 pp Borexino pep 103 be7 b8 cno KamLAND: 2700 mwe c11-decays 102 Borexino: 3500 mwe SNO+: 6080 mwe 10 Jinping: 7500 mwe
1 Counts per 0.1 ktons 1.0 years 5 keV Counts per 0.1 ktons 1.0 years 5 keV 10-1 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 visible energy [MeV]
JinPing - SNO+ Solar 11 Freija Descamps, 09/06/2014 11C background
11C produced by cosmic hitting organic molecules
AnalyticallyAnalytically generatedgenerated spectraspectra withwith 5%/5%/ EE resolutionresolution 101044 pppp BorexinoSNO+ peppep 101033 be7be7 b8b8 cnocno KamLAND: 2700 mwe c11-decaysc11-decays 101022 Borexino: 3500 mwe SNO+: 6080 mwe 1010 Jinping: 7500 mwe
11 Counts per 0.4 ktons 1.0 years 5 keV Counts per 0.1 ktons 1.0 years 5 keV Counts per 0.1 ktons 1.0 years 5 keV 1010-1-1 00 0.20.2 0.40.4 0.60.6 0.80.8 11 1.21.2 1.41.4 1.61.6 1.81.8 22 visiblevisible energyenergy [MeV][MeV]
JinPing - SNO+ Solar 11 Freija Descamps, 09/06/2014 SNO+ solar neutrino spectrum
Assuming initial Sum 228Ac 8B 210Bi Borexino-level 212Bi 7Be 3 214Bi 10 backgrounds are reached CNO 40K pep 234Pa 214Pb 212Po 208Tl Events / kTonne-year 102
10
1 123456 Energy / MeV
JinPing - SNO+ Solar 12 Freija Descamps, 09/06/2014 Assuming initial Borexino- level backgrounds are SNO+ low-energy reached
Sum 228Ac 8B 210Bi 212Bi 7Be 214Bi CNO 40K pep 103 234Pa 214Pb 212Po 208Tl Events / kTonne-year
102
0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 Energy / MeV
JinPing - SNO+ Solar 13 Freija Descamps, 09/06/2014 Assuming initial Borexino- level backgrounds are SNO+ low-energy reached
Sum 228Ac 8B 210Bi 212Bi 7Be 214Bi CNO 40K pep 103 234Pa Sum w/o pep 214Pb 212Po 208Tl Events / kTonne-year
102
0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 Energy / MeV
JinPing - SNO+ Solar 14 Freija Descamps, 09/06/2014 Assuming initial Borexino- level backgrounds are SNO+ low-energy reached
Sum 228Ac 8B 210Bi 212Bi 7Be 214Bi CNO 40K pep 103 234Pa Sum w/o pep 214Pb 212Po 208Tl Events / kTonne-year
102
0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 Energy / MeV
JinPing - SNO+ Solar 15 Freija Descamps, 09/06/2014 Assuming initial Borexino- level backgrounds are SNO+ low-energy reached
Sum 228Ac 8B 210Bi 212Bi 7Be 214Bi CNO 40K pep 103 234Pa Sum w/o pep 214Pb 5% energy scale 212Po 208Tl Events / kTonne-year
102
0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 Energy / MeV
JinPing - SNO+ Solar 16 Freija Descamps, 09/06/2014 Assuming initial Borexino- level backgrounds are SNO+ low-energy reached
Sum 228Ac 8B 210Bi 212Bi 7Be 214Bi CNO 40K pep 103 234Pa Sum w/o pep 214Pb 1% energy scale 212Po 208Tl Events / kTonne-year
102
0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 Energy / MeV
JinPing - SNO+ Solar 17 Freija Descamps, 09/06/2014 Assuming initial Borexino- level backgrounds are SNO+sensitivity studies reached
! Sum 5 10 8B 1 year lifetime 7Be 7 CNO+210Bi 4 ν signals: pep, Be, pep 8 104 39Ar B, CNO 40K 85Kr 30 bkgs 210Po Th chain eqm 103 14C U chain Th chain U chain semi-eqm Extended max L fit 102 50% fid vol Target bkgs 10 Energy scale /resn studies 1 Stat dominated
1
JinPing - SNO+ Solar 18 Freija Descamps, 09/06/2014 Assuming initial Borexino- level backgrounds are SNO+sensitivity studies reached
2 = 419.70163 / 630 105 8B : 679.79 +/- 24.39 7 Be : 1 year53785.86 livetime +/- 3067.64 4 210 10 Bi + CNO : 21105.86 +/- 955.53 (stat) 1 year 2 years pep : 50% fiducial 3553.48 +/- volume 305.40 4 υ signals pep 9.1% 6.5% 103 + 7 bkgs 8B 7.5% 5.4% Sensitivity goals 102 7Be 4% 2.8% pp A few %?
10 CNO ~ 15%?
1 pp depends on 14C, 85Kr CNO depends on 210Bi 123456
JinPing - SNO+ Solar 19 Freija Descamps, 09/06/2014 Assuming initial Borexino- level backgrounds are SNO+sensitivity studies reached
! 8B spectrum Background rejection: 99.8% 214Bi through β - α tagging 90% 208Tl through α - α tagging
JinPing - SNO+ Solar 20 Freija Descamps, 09/06/2014 SNO+ Physics Plan
! Light Water filling now! nucleon decay ! ! Supernova monitoring Scintillator loading backgrounds (spring 2015) Reactor neutrinos Geo neutrinos Geo
Te-loaded scintillator (end 2015) ββ
!
Pure scintillator phase solar neutrinos
JinPing - SNO+ Solar 21 Freija Descamps, 09/06/2014