Post on 21-Dec-2015
S. Dye --- 12/15/05S. Dye --- 12/15/05 Neutrino Geophysics WorkshopNeutrino Geophysics Workshop 11
Hawaii Anti-Neutrino Hawaii Anti-Neutrino ObservatoryObservatory
For the Hanohano collaboration:For the Hanohano collaboration:
Steve DyeSteve DyeUniversity of Hawaii at ManoaUniversity of Hawaii at Manoa
andand
Hawaii Pacific UniversityHawaii Pacific University
S. Dye --- 12/15/05S. Dye --- 12/15/05 Neutrino Geophysics WorkshopNeutrino Geophysics Workshop 22
Outline of TalkOutline of Talk
ObjectivesObjectives• 15% measurement of mantle U/Th 15% measurement of mantle U/Th
neutrinos (Qneutrinos (QU+ThU+Th= 8 ± 1 TW)= 8 ± 1 TW)
• Search for >1TW geo-reactorSearch for >1TW geo-reactor MethodsMethods
• Big “KamLAND” in the deep oceanBig “KamLAND” in the deep ocean ConclusionsConclusions
S. Dye --- 12/15/05S. Dye --- 12/15/05 Neutrino Geophysics WorkshopNeutrino Geophysics Workshop 33
Institutions and PersonnelInstitutions and Personnel
University of Hawaii at ManoaUniversity of Hawaii at ManoaSteve Dye, Peter Grach, Gene Guillian, Steve Dye, Peter Grach, Gene Guillian,
John Learned (PI), Jelena Maricic, John Learned (PI), Jelena Maricic,
Shige Matsuno, Sandip Pakvasa, Gary Varner,Shige Matsuno, Sandip Pakvasa, Gary Varner,
Mavourneen WilcoxMavourneen Wilcox
Makai Ocean EngineeringMakai Ocean EngineeringTore Leraand, Joe Van Ryzin (PI) Tore Leraand, Joe Van Ryzin (PI)
+ Others+ Others
S. Dye --- 12/15/05S. Dye --- 12/15/05 Neutrino Geophysics WorkshopNeutrino Geophysics Workshop 44
Funding and SupportFunding and Support
CEROSCEROS** 1-year study funds 1-year study funds• Critical issues of deep ocean deploymentCritical issues of deep ocean deployment
Implosion of PMT modulesImplosion of PMT modules Optical properties of scintillating oilOptical properties of scintillating oil Low power electronicsLow power electronics Data transmissionData transmission
• Detector design criteriaDetector design criteria Size and sensitivitySize and sensitivity
UH Physics support infrastructureUH Physics support infrastructure
* Center of Excellence for Research in Ocean Sciences* Center of Excellence for Research in Ocean Sciences
S. Dye --- 12/15/05S. Dye --- 12/15/05 Neutrino Geophysics WorkshopNeutrino Geophysics Workshop 55
Predicted Geo-neutrino SignalPredicted Geo-neutrino Signal
F. Mantovani et al., Phys. Rev. D 69, 013001 (2004).
(1032 proton-yrs = 1 TNU ≈ 1.2 kT-y of KamLAND oil)
S. Dye --- 12/15/05S. Dye --- 12/15/05 Neutrino Geophysics WorkshopNeutrino Geophysics Workshop 66
Geo-neutrino sourcesGeo-neutrino sources
Japan Japan
~~11::33
mantle mantle : : crust crust
Hawaii Hawaii
~~33::11
mantlemantle : : crustcrust
Plot courtesy of S. EnomotoPlot courtesy of S. Enomoto
S. Dye --- 12/15/05S. Dye --- 12/15/05 Neutrino Geophysics WorkshopNeutrino Geophysics Workshop 77
Predicted Mantle-neutrino Predicted Mantle-neutrino Signal in Scintillating Oil Signal in Scintillating Oil
Raghavan Raghavan et al.et al. (1998) (1998)
U(ppm) = 0.01U(ppm) = 0.01
ΦΦ(U) = 7.3 TNU(U) = 7.3 TNU**
ΦΦ(Th) = 1.9 TNU(Th) = 1.9 TNU**
ΦΦ(tot) = 9.2 TNU(tot) = 9.2 TNU**
S = 7.9 per kT-yS = 7.9 per kT-y
Enomoto Enomoto thesisthesis (2005) (2005)
U(ppm) = 0.012U(ppm) = 0.012
ΦΦ(U) = 8.1 TNU(U) = 8.1 TNU
ΦΦ(Th) = 2.2 TNU(Th) = 2.2 TNU
ΦΦ(tot) = 10.3 TNU(tot) = 10.3 TNU
S = 8.8 per kT-yS = 8.8 per kT-y
S = Φ(TNU) x 0.85(kT/TNU)
* Corrected for oscillation
S = 7.9 per kT-y (Mantovani this workshop)S ~ 8.5 per kT-y (Lisi this workshop)
S. Dye --- 12/15/05S. Dye --- 12/15/05 Neutrino Geophysics WorkshopNeutrino Geophysics Workshop 88
Geo-neutrino SignalGeo-neutrino Signal
Geo-nuanalysis
Reactor-nuanalysis
S. Dye --- 12/15/05S. Dye --- 12/15/05 Neutrino Geophysics WorkshopNeutrino Geophysics Workshop 99
Geo-neutrino Signal plus Known Geo-neutrino Signal plus Known BackgroundsBackgrounds
S. Dye --- 12/15/05S. Dye --- 12/15/05 Neutrino Geophysics WorkshopNeutrino Geophysics Workshop 1010
Geo-neutrino Signal + Background Geo-neutrino Signal + Background with Geo-reactorwith Geo-reactor
S. Dye --- 12/15/05S. Dye --- 12/15/05 Neutrino Geophysics WorkshopNeutrino Geophysics Workshop 1111
Significance and SignalsSignificance and Signals
Signal significance: Signal significance: σσ = S / √(S+B) = S / √(S+B) Mantle-neutrino signalMantle-neutrino signal
~80 events per 10 kT-y (1.7<E~80 events per 10 kT-y (1.7<Eνν(MeV)<3.4)(MeV)<3.4)
1 TW Geo-reactor signal1 TW Geo-reactor signal38 events per 10 kT-y (3.4< E38 events per 10 kT-y (3.4< Eνν(MeV)<9.3)(MeV)<9.3)
Set Set σσ ≥ 5 for discovery (P>99.99%) ≥ 5 for discovery (P>99.99%)σσ=5 requires B<20 events per 10 kT-y=5 requires B<20 events per 10 kT-y
S. Dye --- 12/15/05S. Dye --- 12/15/05 Neutrino Geophysics WorkshopNeutrino Geophysics Workshop 1212
Geo-neutrino signature in Geo-neutrino signature in Scintillating OilScintillating Oil
p
+
Prompt signalEvis=Eν- En - 0.8 MeV
Delayed signal
Evis = 2.2MeVΔt ≈ 200µs Δr ≈ 10cm
Scintillating oil viewed with PMTs measures energy but not direction of geo-neutrino
γνe fromβ-decay onU/Th chain
Geo-neutrino
S. Dye --- 12/15/05S. Dye --- 12/15/05 Neutrino Geophysics WorkshopNeutrino Geophysics Workshop 1313
Identified BackgroundsIdentified Backgrounds
Cosmic ray muons
alpha source
Rad
ioacti
ve m
ate
rials
fast neutrons
spallationproducts
•Secondary cosmic raysFast neutronsSpallation- 9Li
•Dirty scintillating oil 13C(α,n)16O
•Impurities outsideAccidental coincidences
•AntineutrinosNuclear reactors
Earth’s crust
TargetVolume
μ±
μ±
S. Dye --- 12/15/05S. Dye --- 12/15/05 Neutrino Geophysics WorkshopNeutrino Geophysics Workshop 1414
Background ReductionBackground Reduction
Location, location, locationLocation, location, location• Far from nuclear reactors and Far from nuclear reactors and
continental crustcontinental crust• >4000 m.w.e. overburden>4000 m.w.e. overburden
Clean, clean, cleanClean, clean, clean• < 1/40 KamLAND < 1/40 KamLAND 210210Po levelPo level• Radio-pure detector materialsRadio-pure detector materials
S. Dye --- 12/15/05S. Dye --- 12/15/05 Neutrino Geophysics WorkshopNeutrino Geophysics Workshop 1515
Backgrounds: Mantle-neutrino Backgrounds: Mantle-neutrino measurementmeasurement
Scale KamLAND Scale KamLAND ((NatureNature 436436 2005) 2005)
• x 12 exposurex 12 exposure• 1/40 1/40 210210PoPo
Total expected Total expected 86±586±5
Geo-reactor adds 19 Geo-reactor adds 19 events per TW events per TW
1.7<E1.7<Eνν(MeV)<3.4(MeV)<3.4 Rate (10 kT-y)Rate (10 kT-y)-1-1
99Li (4 km)Li (4 km) 0 ± 00 ± 0
210210PoPo 13 ± 313 ± 3
AccidentalsAccidentals (<) 30 ± 1(<) 30 ± 1
Known ReactorsKnown Reactors (<) 14 ± 1(<) 14 ± 1
Crust neutrinosCrust neutrinos 29 ± 529 ± 5
TotalTotal 86 ± 586 ± 5
S. Dye --- 12/15/05S. Dye --- 12/15/05 Neutrino Geophysics WorkshopNeutrino Geophysics Workshop 1616
Backgrounds: Geo-reactor searchBackgrounds: Geo-reactor search
Scale KamLAND Scale KamLAND ((PRLPRL 9494 2005) 2005)• x 13 exposurex 13 exposure• 1/40 1/40 210210PoPo
• RRtargettarget= 5m= 5m Total expected 36±2Total expected 36±2 1.2 TW discovery 1.2 TW discovery
thresholdthreshold
3.4<E3.4<Eνν(MeV)<9.3(MeV)<9.3 Rate (10 kT-y)Rate (10 kT-y)-1-1
99Li (4 km)Li (4 km) 4 ± 14 ± 1
210210PoPo 3 ± 23 ± 2
AccidentalsAccidentals 1 ± 01 ± 0
Commercial Commercial ReactorsReactors
28 ± 128 ± 1
TotalTotal 36 ± 236 ± 2
S. Dye --- 12/15/05S. Dye --- 12/15/05 Neutrino Geophysics WorkshopNeutrino Geophysics Workshop 1717
Site SelectionSite Selection
Many sites considered- best is same as DUMAND
S. Dye --- 12/15/05S. Dye --- 12/15/05 Neutrino Geophysics WorkshopNeutrino Geophysics Workshop 1818
HanohanoHanohano
S. Dye --- 12/15/05S. Dye --- 12/15/05 Neutrino Geophysics WorkshopNeutrino Geophysics Workshop 1919
Current StatusCurrent Status
Prototype electronics fabricated and Prototype electronics fabricated and tested- tested- G. Varner, M. WilcoxG. Varner, M. Wilcox
Scintillating oil pressure tests in Scintillating oil pressure tests in preparation- preparation- P. GrachP. Grach
Implosion tests next yearImplosion tests next year Ocean demonstration of prototype Ocean demonstration of prototype
detector to followdetector to follow
S. Dye --- 12/15/05S. Dye --- 12/15/05 Neutrino Geophysics WorkshopNeutrino Geophysics Workshop 2020
Electronics prototypesElectronics prototypes
PMT base Digitizer
S. Dye --- 12/15/05S. Dye --- 12/15/05 Neutrino Geophysics WorkshopNeutrino Geophysics Workshop 2121
ConclusionsConclusions
10 kT-y exposure of Hanohano would10 kT-y exposure of Hanohano would• Measure BSE mantle U/Th to ~11%Measure BSE mantle U/Th to ~11%• Search for ~1TW geo-reactorSearch for ~1TW geo-reactor
Hanohano in design stageHanohano in design stage• 4 kT target volume “KamLAND”4 kT target volume “KamLAND”• Deep ocean deployment for few yearsDeep ocean deployment for few years