Geo-neutrinos

Outline • Antineutrino detection • Geology fundamentals • Geo-neutrinos and earth models• Detection projects• Observational strategies• Geo-neutrino direction spectra• Geo-reactor ranging

Steve DyeHawaii Pacific University

University of Hawaii

Antineutrino Detection

PMTs measure position and amount of deposited energy

γ

e+

e-

γ

n p+

γ

Prompt event depositsenergy of Eν-0.8 MeV

Delayed event depositsenergy of 2.2 MeV

p+νe

Antineutrino (Eν>1.8 MeV) interacts with free proton

SLAC 8/25 2

Reines and Cowan

At Hanford, Washington

Savannah River

Reines, F., Rev. Mod. Phys. 68 (1996) 317-327.

Over 5 decades ofantineutrino detection

SLAC 8/25 3

Earth Origin

Planets form from solar nebula

Formation time ~10-100 Ma

1.E+02

1.E+03

1.E+04

1.E+05

1.E+06

1.E+07

1.E+08

1.E+02 1.E+03 1.E+04 1.E+05 1.E+06 1.E+07

Sol

ar p

hoto

sphe

re(a

tom

s S

i = 1

E6)

C1 carbonaceous chondrite(atoms Si = 1E6)

H

CN

Li

B

O

Carbonaceous chondrite

SLAC 8/25 4

Standard Model of Earth

Bulk earth (chondrite) = Primitive mantle (komatiite) + Core (Fe/Ni)

Primitive mantle (Bulk Silicate Earth) = Mantle + Crust

SLAC 8/25 5

Earth Structure- Geophysics

Detailed seismological description:Preliminary Reference Earth Model (PREM)A.M. Dziewonski, D.L. Anderson,Phys. Earth Planet Inter. 25 (1981) 297.

Seismology defines earth structure

SLAC 8/25 6

Earth Composition- Geochemistry

U, Th, K principal heat-producing elements

20±4 TW

Bulk Silicate Earth model:~1/2 of U, Th, K in crust~1/2 of U, Th, K in mantle~no U, Th, K in core

What are amount and distribution of

U, Th, K in crust and mantle?

SLAC 8/25 7

Earth Heat- Geodynamics

Surface heat flow interpretations:Jaupart et al. (2008) Aq=46±3TWHofmeister and Criss (2004) Aq=33±1TW

Surface Heat FlowMeasurement Sites

Heat flow probe-thermal conductivity,dT/dx

Heat conduction-q = -k dT/dx

SLAC 8/25 8

Thermal Earth: MC(∂T/∂t) = Mh - Aq

∂T/∂t = (Mh-Aq)/MC∂T/∂t = (-26±5)/MC∂T/∂t = (-13±4)/MC

Radiogenic heat estimate:(hU ≈ hTh≈ ⅜hK)

McDonough and Sun (1995) Mh=20±4TW

238U

232Th

40K

Radiogenic Heat Production

Surface heat flow interpretations:Jaupart et al. (2008) Aq=46±3TWHofmeister and Criss (2004) Aq=33±1TW

Surface Heat Flow

U = Mh/AqU = 0.43±0.09

U = 0.61±0.12

Radiogenic heat estimate dominates uncertainty in Urey ratio and cooling rate calculations

SLAC 8/25 9

Terrestrial Antineutrinos

238U232Th40K

νe + p+ → n + e+

1.8 MeV Energy Threshold

212Bi

228Ac

232Th

1α, 1β

4α, 2β

208Pb

1α, 1β

νe

νe

2.3 MeV

2.1 MeV

238U

234Pa

214Bi

1α, 1β

5α, 2β

206Pb

2α, 3β

νe

νe2.3 MeV

3.3 MeV

40K 40Ca1β

Terrestrial antineutrinos from uranium and thorium are detectable

SLAC 8/25 10

Geo-neutrinos – Crust

Constrain models with 15% measurements

Crust thickness & densityBassin, C., Laske, G. and Masters, G. (2000)

7 layers in 16,200 tiles each 2° x 2°360 crust types!!!

U & Th concentrationsRudnick, R.L. and Fountain, D.M. (1995)

a(U) 2.8, 1.6, 0.2 ppma(Th) 10.7, 6.1, 1.2 ppm

Model Ref. S86 W94 RF95 WT84 TM85

h (μW m-3) 1.03 1.31 1.25 0.93 0.92 0.58

H (TW) 8.59 10.93 10.42 7.76 7.67 4.84

% difference 0 +31 +25 -7 -8 -42

Assume geo-neutrino flux scales with heat production: requires detailed study

SLAC 8/25 11

Geo-neutrinos – Mantle

Mantle model typically radial-symmetric

Model Reference H (TW) TNU % diffTH05 PEPI (2005) 7.4 6.9 -22

TKH06TKH06 Chem Geol (2006)Chem Geol (2006) 11.411.4 8.68.6 -3

MCFL04 (ref)MCFL04 (ref) Phys Rev D (2004)Phys Rev D (2004) 10.910.9 8.98.9 0

EOIS07EOIS07 EPSL (2007)EPSL (2007) 11.211.2 10.010.0 +12

KT97KT97 Chem Geol (1997)Chem Geol (1997) 12.712.7 10.910.9 +22

TPW01-IITPW01-II JGR (2001)JGR (2001) 18.218.2 15.115.1 +70

TPW01-ITPW01-I JGR (2001)JGR (2001) 25.725.7 22.022.0 +147

Constrain models with ~10% measurements

} ΔH ~ 10%but

Δφ ~ 25%

SLAC 8/25 12

Earth Heat

Surface heat flow does not constrain

radiogenic heat production

Shaw 1986

Taylor-McLennan 1985

To

lsti

kh

in-H

ofm

an

n 2

00

5

Tu

rco

tte

-Pa

ul-

Wh

ite

20

01

Jaupart-Labrosse-Mareschal 2007

SLAC 8/25 13

Mantle Heat vs Rate

Jaupart-Labrosse-Mareschal 2007

Tension betweensome models and

geo-dynamics

SLAC 8/25 14

Terrestrial Antineutrino Reference Model

CRUST 2.0 w/ PREM interior

U, Th, K concentrations incrust and upper mantle fromaverage of published values

Lower mantle constrained by mass balance and-232Th/238U = 3.9 ; 40K/238U = 1.36

F. Mantovani et al., Phys. Rev. D 69 (2004) 013001.

a(238U) a(232Th) a(40K)

CCU 2.5 ppm 9.8 ppm 3.06 ppm

CCM 1.6 ppm 6.1 ppm 1.99 ppm

CCL 0.62 ppm 3.7 ppm 0.86 ppm

OC 0.1 ppm 0.22 ppm 0.15 ppm

MU 6.5 ppb 17.3 ppb 9.3 ppb

ML 13.2 ppb 52.0 ppb 19 ppb

SLAC 8/25 15

Reactor Antineutrinos- Background

Spectra overlap

Neutrino Energy

Reactor flux:• can not be eliminated• grows with each new

reactor• minimize by distance

SLAC 8/25 16

Detector Location Status Free protons (x1032 p+)

Crust(TNU)

Mantle(TNU)

Reactor(TNU)

KamLAND Japan Operating 0.62 25.5 8.9 207.3

Borexino Italy Operating 0.18 31.7 8.9 39.1

SNO+ Canada Construct 0.57 41.8 8.9 68.8

Homestake Dakota Discuss 1.80 42.3 8.9 12.0

Baksan Caucasus Discuss 4.00 41.8 8.9 13.5

LENA Finland Proposed 36.7 42.5 8.9 25.8

Hanohano Hawaii Proposed 7.34 3.5 8.9 1.64

Geo-neutrino Detector Parameters

Reference model rates corrected for new νosc parameters

SLAC 8/25 17

)/27.1(sin)2(sin1 2

21

2

12

2

eeeELmP

Kamioka Gran Sasso

Sudbury Homestake

PyhasalmiBaksan

201 reactors worldwide with

total power 1.064 TW

Reactor Spectra at Detection Sites

SLAC 8/25 18

Borexino- in Italy

Primary Goal

νe + e- → νe + e-

Solar neutrino-electron scattering

No terrestrial antineutrino results yet

• operating since 5/16/07• 300 tonnes LS• 2200 PMTs • ~30% PC coverage

SLAC 8/25 19

KamLAND- in Japan

νe + p → n + e+

Reactor antineutrinoinverse beta

Primary Goal

• operating since 3/9/02• 1000 tonnes LS• 1879 PMTs

Terrestrial antineutrinoresults 2004, 20082.44x1032 proton-yr

SLAC 8/25 20

KamLAND Geo-neutrino Results

U, Th Geo-nu Flux (106 cm-2 s-1)

Observed Predicted

KL-04 5.7 ± 4.2 4.14Enomoto et al. 2007

3.96Mantovani et al. 2004KL-08 4.4 ± 1.6

Prompt Event Energy Spectrum

arXiv:0801.4589v2 [hep-ex] 5 Feb 2008

Best fit to data for Th/U=3.9 gives 73±27 (2.7σ) events, consistent with reference model, a precision of 37%

Large background limits sensitivity to geo-neutrinos

No evidence yet for U-series geo-neutrinos

SLAC 8/25 21

KamLAND U & Th Flux

Shaw 1986

Taylor-McLennan 1985

Tu

rco

tte

-Pa

ul-

Wh

ite

20

01

To

lsti

kh

in-H

ofm

an

n 2

00

5

Ref (Mantovani et al. 2004)

Re

f

KamLAND flux measurementdoes not constrain models

SLAC 8/25 22

Future Terrestrial Antineutrino Results

Hanohano

LENA

Baksan

SLAC 8/25 23

Predicted Antineutrino Source Fractions

0%

20%

40%

60%

80%

100%

KamLAND Borexino SNO+ LENA Homestake Baksan Hanohano

Reactor

Crust

Mantle

Future detector sites better for terrestrial antineutrino flux measurements

SLAC 8/25 24

Fractional Uncertainty: Crust, Mantle Rates

rmn

nmrnn

c

c omr

2222

rmcn Rate of antineutrino events:

omr ,,,Uncertainties

Fractional uncertainties

Background subtraction requires model assumption

rcn

ncrnn

m

m ocr

2222

SLAC 8/25 25

Background-subtracted Crust Rate Precision

KamLAND

Borexino

SNO+

• Mantle rate m=8.9 TNU• Exposure error σe=0.03• Reactor error σr=0.03• Oscillation error σo=0.03• Mantle error σm=0.20• Solid- 1.0c• Dash- 1.2c• Dots- 0.8c

KL BX S+

c 25.5 31.7 41.8

r 207.3 39.1 68.8

SNO+ has potential for20% measurement of

background-subtractedcrust rate in 3-6 years

SLAC 8/25 26

Crust Rate…future

DU BK LE

c 42.3 41.8 42.5

r 12.0 13.5 25.8

• Mantle rate m=8.9 TNU• Exposure error σe=0.03• Reactor error σr=0.03• Oscillation error σo=0.03• Mantle error σm=0.20• Solid- 1.0c• Dash- 1.2c• Dots- 0.8c

All have potential for10% measurement of

background-subtractedcrust rate

2.5-kt DUSEL

5-kt Baksan

50-kt LENA

SLAC 8/25 27

Fractional Uncertainty: Crustal Rate Difference

Maximize Δn , ε ; Minimize r, σr , σe , σo

1212

21

22

221

22

221

22

21122 )()()(

rrnn

nnnnrrnn

c

c oer

rmcn rates:

exposure: ST

errors: σr ,σe ,σo

Detection parameters:

n2 = c2 + m + r2

n1 = c1 + m + r1

c2 – c1 = (n2 – r2) – (n1 – r1)

Compare measurements at two sites:

Construct fractional uncertainty in crustal rate difference:

Insensitive to mantle model

SLAC 8/25 28

KamLAND – Borexino – SNO+

Solid σr =σe =σo =0.03; Dots σr =σe =σo =0.01; Dash σr =σe =σo =0.05

Detectors capable of geo-neutrino observation,

which are existing or under construction,

are not able to resolve crustal models

independent of BSE

• KamLAND – Borexino– ~250%

• KamLAND – SNO+– ~100%

• Borexino – SNO+– ~80%

KamLAND - Borexino

KamLAND - SNO+

Borexino - SNO+

SLAC 8/25 29

Continental vs. Oceanic

• Hanohano – KamLAND– ~60%

• Hanohano – Borexino– ~20%

• Hanohano – SNO+– ~16%

Combinedcontinental and

oceanic geo-neutrino observation can constrain crustal

models independentlyof BSE only aftervery long time

Hanohano – KamLAND

Hanohano – Borexino

Hanohano – SNO+

Solid σr =σe =σo =0.03; Dots σr =σe =σo =0.01; Dash σr =σe =σo =0.05

SLAC 8/25 30

HH – 2.5-kt DUSEL

HH – 5-kt Baksan

HH – 50-kt LENA

Solid σr =σe =σo =0.03; Dots σr =σe =σo =0.01; Dash σr =σe =σo =0.05

• Hanohano – 2.5-kt DUSEL– ~8%

• Hanohano – 5-kt Baksan– ~8%

• Hanohano – 50-kt LENA– ~9%

Combinedcontinental and

oceanic geo-neutrino observation can constrain crustal

models independentlyof BSE in

reasonable time

Continental vs. Oceanic – Future

SLAC 8/25 31

Background-subtracted mantle rate precision

Solid σr =σe =σo =0.03; Dots σr =σe =σo =0.01; Dash σr =σe =σo =0.05

• Crust rate c=3.6 TNU• Crust error σc=0.20

Exposure at mid-oceanic sitehelps constrain mantle models but does not

determine U and Thdistribution

SLAC 8/25 32

Boundaries in a 1-Dimensional Mantle

Nadir anglecos(θ) = (Re

2-ρ2)1/2 /Re

Re= 6371 km

ρCMB = 3480 km

cos(θCMB) = 0.84

ρTZ = 5701 km

cos(θTZ) = 0.45

Core

CMB

Transition Zone

Mantle

33.1°

63.5°

ρ

Re

Symmetry enhances signal

SLAC 8/25 33

Resolving Mantle Models

Layered Mantle Convection

Whole Mantle Convection

Angular distribution of antineutrinos identifies mantle layers with different U, Th concentrations

KT97

TKH06

TZ CMB

Outer core

SLAC 8/25 34

Geo-neutrino Directions- Crust

Could the crust and mantle be separately resolved?

Need to add site-specific crustal signal to

model-dependent mantle signal

SLAC 8/25 35

68.3% CL

99.7% CL95.5% CL

Preliminary Angular Resolution Study

KT97

TKH06

Compare red/blue ratiosCalculate exposure to resolve

Crust signalmostly here

Resolution of mantle models depends on angular resolutionSLAC 8/25 36

Measuring Antineutrino Direction

θ n

Neutron Kinetic Energy (keV)

Neutron Emission Angle

Can we build a nuebar telescope?• Good for geology, DSNB search • Would be an interesting study

• Interaction kinematics• Neutron absorption• Position resolution• Scintillator properties

Δθ

Prompt e+

νe Neutrino direction

Reconstructed event direction

Δθ

Delayed n capture

SLAC 8/25 37

Geo-neutrino Conclusions

SLAC 8/25 38

• Remote sensing of main heat-producing elements- U, Th• Demonstrated by KamLAND

• Detected flux depends on quantity and distribution of U, Th• >3 km water equivalent & far from reactors

•Disentangle contributions from crust and mantle with• Continental AND Oceanic observatories• 2.5-kt DUSEL (40M$) and 10-kt Hanohano (>100M$)

• Distribution of U, Th in mantle may require direction• Promising developments in progress

Neutrino Mixing Discriminates Geo-reactor Models

SLAC 8/25 39

A Natural Fission ReactorPredicted by P.K. Kuroda,

J. Chem. Phys. 25, 781 (1956). Discovered at Oklo in west Africa

G.A. Cowan, Sci. Am. 235, 36 (1976).

• 235U/238U ~0.03 (~4 x present) 2 Gy ago• Water concentrates deposit & moderates n

• Reactor released ~15 GW-yr of energy over few 105 yr

SLAC 8/25 40

Deep-Earth Geo-reactor Models

Core-Mantle Boundary P~5TWR.J. de Meijer & W. van Westrenen

S. Afr. J. Sci. 104, 111 (2008)

r=3480 km

r=1222 km Inner Core Boundary P~20-30 TWV.D. Rusov et al.,

J. Geophys. Res. 112, B09203 (2007)

Earth Center P~3-10 TWJ.M. Herndon,

Proc. Nat. Acad. Sci. 93, 646 (1996)

Proposed at 3 depths w/ loosely definedpower output sufficient to explain:

• surface heat flow > radiogenic heat 33-46 TW > ~20 TW•3He/4He OIB>MORB

tritium fission product- 3H→3He+β-+ν

Deep-earth Geo-reactor:Hypothetical and very speculative

Possible and not ruled out

SLAC 8/25 41

Experimental Constraint

- Nuclear plant

KamLAND exposure 2.44x1032p+-yrand solar neutrino data set upper limit to power

of earth-centered geo-reactor

P < 6.2 TW (90% C.L.)

Abe et al., PRL 100, 221803 (2008)

55 Japanesenuclear power reactor units

SLAC 8/25 42

More Sensitive Search Possible

Oceanic antineutrino observatoryoperating far from reactors

in deep ocean

Signal/Background ~0.8/TW

8.5x1032 p+-yr exposuresets P < 0.5 TW

at >95% C.L.

Or measure power to ~10%if P~ few TW at earth center

Dye et al., EMP 99, 241 (2006)

SLAC 8/25 43

Uncertainties- Power vs Location

KamLAND power limit translatesto 1.3 – 15 TW allowing

geo-reactor position along diameter through core

Locating geo-reactor source position would lead to more

precise power estimateand discriminate

geo-reactor models

What if geo-reactor not earth-centered?Models suggest 3 possible

deep-earth locations:Earth center

Inner core boundaryCore-mantle boundary

…or use neutrino oscillation pattern tomake the map

SLAC 8/25 44

Could consider antineutrino direction measurement

Excellent recent progress at RCNSalthough technology

not fully available

Distortion of Energy Spectrum

)/27.1(sin)2(sin1 2

21

2

12

2

eeeELmP

52

21

12

2

1059.7

47.0tan

m

eV2

Abe et al., PRL 100, 221803 (2008)

Mixing parameters from global solar + reactor fit

2

2

2.3

8.0exp)4.1(

)(

e

e

e

EE

EN

Reactor spectrum approximated Reactor antineutrino energy spectrum

Earth centerd=6370 km

Core-mantled=2890 km

δE=0

δE=0

SLAC 8/25 45

Energy Resolution

Distortions well preserved with 3%√E energy resolution

Idealized energy spectra: TW-1033p+-yr

δE=6%√E δE=3%√E

6370 km

5150 km

2890 km

Benchmark:KamLAND visible energy resolution δE/E=6.5%/√E

8.0e

EE Visible energy resolution

determined by scintillationlight collection:

•Photocathode coverage•Photocathode QE

•Scintillation light output

Visible energy related to antineutrino energy

SLAC 8/25 46

Improving Energy Resolution

Benchmark- KamLAND at ~6%Goal- Increase light collection x4 to achieve 3%

3%√E possible

Increase light output with LAB-based scintillating oil

x ~1.7 (M. Chen 2006)

Increase photocathode coverage to SNO-like (55%)

x ~1.6 (B. Aharmin et al. 2007)

Increase PC quantum efficiency x ~1.6

(R. Mirzoyan et al. 2006)

SLAC 8/25 47

)/27.1(sin)2(sin1 2

21

2

12

2

eeeELmP

Use Rayleigh Power to

estimate significance ofspectral distortions

NZ

N

i

i

N

i

i

22

sincos

minmax

minmax

2

2127.1

2

EE

EE

mLind

Independent Distance~150 km

ii ELm /27.1 2

21For each event in the spectrum

Test significance of spectrum at distances L=500-8000 km

Rayleigh Power Estimates Spectral Significance

Distance limitations: spectrum must modulate,

Lind is minimum;modulations must be resolved,

energy resolution sets maximum

Introduced by Lord Rayleigh tostudy directions of pigeon flight

Used to test for periodicity oflight curves in astronomy

amplitude modulation

SLAC 8/25 48

Measuring Distance to Reactor

Power peaks at correct distanceFWHM ~1000 km

δE=6%√E δE=3%√E

Oversampled x10

2890 km

5150 km

6370 km

δE=3%√EδE=6%√E

Rayleigh Power DistributionsIdealized energy spectra: TW-1033p+-yr

SLAC 8/25 49

Resolving Distances to Multiple Sources

Method capable of finding discrete sources atdifferent distances

Idealized energy spectrum with δE=3%√E from TW-1033p+-yr exposure to sources at:

• CMB• Inner core boundary- near• Earth center• Inner core boundary- far

Rayleigh power distribution resolvesdiscrete sources at different distances

separated by > ~500 km

SLAC 8/25 50

Distributed Sources

Method has potential for finding distributed sources

r=5km

r=50km

r=500km

Single source

Near and farsurfaces

resolved!!!Idealized energy

spectra with δE=3%√E from

TW-1033p+-yrexposure to

sourcedistributed

uniformly on a geo-centric,

spherical shell:different radii

SLAC 8/25 51

Distributed Sources

r=500km

r=1222km

r=3480km

Peaks due tonear and far surfacesjust poking up above

noise: potential forinner core boundary?

Idealized energy spectra with δE=3%√E from TW-1033p+-yr exposure Geo-centric source uniformly distributed on spherical shell

CMB

Inner core

SLAC 8/25 52

SLAC 8/25 53

Assessing Exposure Requirements

• Randomly sample idealized event spectra

• Number of sampled events determines exposure

• Generate Rayleigh power distribution

• Test if peak within ± Lind (150 km) of “true” distance

• Repeat for 1000 spectra at each exposure

• Efficiency is fraction of “correct” distance measurements

Earth-centered: r = 6370 km

Inner core boundary: r = 5150 km

Core-mantle boundary: r = 2890 km

95%

20

6

0.4

Exposures w/ efficiency ε=0.99 σdistance≈ Lind ≈ 150 km

Efficiency Increases with Exposure

Greater distance requireslarger exposure

SLAC 8/25 54

• Background not included:• Reactor antineutrinos- far away from commercial plants• Cosmic rays- overburden > 3000 m.w.e.• Geo-neutrinos- far away from continents

• Solution: Observe from mid-Pacific location- Hanohano

SLAC 8/25 55

Limitations of Study

Geo-reactor Ranging Conclusions

SLAC 8/25 56

• Neutrinos are marvelous tools

• L/E for reactor antineutrinos at deep-earth distances good match for solar mass-squared differences

• Energy spectrum distortions resolved with high light collection (~x4 KL)- aim for δE=3%√E

•Distances to deep-earth geo-reactors measured to ± few 100 km using Rayleigh power scan

•Suitable for discriminating geo-reactor models with project like Hanohano

Hanohano- Deep Ocean Anti-Neutrino ObservatoryHanohano- Deep Ocean Anti-Neutrino Observatory

Project OverviewProject Overview• portable 10 kt scintillator• deploy and recover• site determines science• project cost >$100M, operate >10y• international collaboration of ~100• design study completed 2006

Custom BargeCustom Barge• tow to any ocean• 10m draft, fits harbors• onboard

– oil purification– RO water– detector support

• detector to 100 kt• 9 kt max to fit Panama

Detector DesignDetector Design• 10-kt scintillating oil• inverse-beta coincidence• 2-m H2O veto,1-m oil buffer• PMTs in glass spheres• carbon steel outer tank• SS inner tank• volume change compensation• power <5 kW• data rate few Gb/s

Deployment/RecoveryDeployment/Recovery• tow to site, transfer fluids• lower anchor, pass cable• release anchor, fill hoses• descent rate ~100 m/min• take data for year or more• max depth 6700 m• release anchor to recover• ascent rate ~100 m/min

SLAC 8/25 57

Reactor Site: Neutrino ParametersReactor Site: Neutrino ParametersPrecision measurements in several years!• optimum baseline ~50-60 km• 5-6 GW sites available with 1-3 km depth• need study of overburden requirement• analysis w/ systematics- M. Batygov (UH)• solar- Δm2

21, sin2(2θ12) to ~1% in 2y, 4y• if sin2(2θ13)>0.05, then

– Δm231 to ~1% in 2y

– mass hierarchy in 5y

Plots by M. Batygov, UH

Hanohano- Particle Physics & Geo/Astro StudiesHanohano- Particle Physics & Geo/Astro StudiesDeep Ocean Site: Geo-nu & Solar-nuDeep Ocean Site: Geo-nu & Solar-nuGeo-neutrino measurements• study origin, composition, distribution Pearth

• 3-4 km depth to filter cosmic ray muons• resolution of mantle models • synergy with continental observations• sensitive test of geo-reactor hypothesis• locate geo-reactor if existingSolar-neutrino measurements• pep and CNO solar neutrinos

– >4 km depth for signal/noise>1– 55,000 events/y– probe vacuum/matter transition, NSI

All Sites: SN and proton decay searchAll Sites: SN and proton decay searchSupernova neutrino measurements• standard galactic core collapse SN

– ~5000 CC & NC events in 10 s– measure SN & neutrino parameters

• observe relic SN neutrinos 1-4/y (DSNB)SUSY proton decay search- GUT test• p→νK+, τ/B>1034y w/ 10-y exposure

P=

5 G

W, δ

E=

2.5%

/√E

SLAC 8/25

58

Backup slides

SLAC 8/25 59

Comparing Crustal Rate Differences

• c2=40 TNU• Solid c1=30 TNU• Dash c1=20 TNU• Dots c1=10 TNU• Dot-dash c1=5 TNU• Mantle: m =10 TNU• Reactor fraction: r =0.1• Reactor error: σr =0.0• Exposure error: σe =0.0• Oscillation error: σo =0.0• All detectors 1032 p+

<20% possibleLarger Δn, ε better

SLAC 8/25 60

Changing Mantle Rate

δm not critical

• Mantle – Dash: m =20 TNU

– Solid: m =10 TNU

– Dots: m =0 TNU

• Reactor fraction: r =0.1

• Reactor error: σr =0.0

• Exposure error: σe =0.0

• Oscillation error: σo =0.0

• All detectors 1032 p+

Δc=40-30=10 TNU

Δc=40-20=20 TNU

Δc=40-10=30 TNU

Δc=40-5=35 TNU

SLAC 8/25 61

Changing Reactor Rate

r critical

• Mantle: m =10 TNU• Reactor fraction:

– Dash: r =10

– Solid: r =1.0

– Dots: r =0.1

• Reactor error: σr =0.0

• Exposure error: σe =0.0

• Oscillation error: σo =0.0

• All detectors 1032 p+

Δc=40-30=10 TNU

Δc=40-20=20 TNU

Δc=40-10=30 TNU

Δc=40-5=35 TNU

SLAC 8/25 62

Changing Reactor Error

σr important

• Mantle: m =10 TNU• Reactor fraction: r =1.0• Reactor error:

– Dash: σr =0.10

– Solid: σr =0.05

– Dots: σr =0.0

• Exposure error: σe = 0.0

• Oscillation error: σo = 0.0

• All detectors 1032 p+

Δc=40-30=10 TNU

Δc=40-20=20 TNU

Δc=40-10=30 TNU

Δc=40-5=35 TNU

SLAC 8/25 63

Changing Exposure Error

σe more important

• Mantle: m =10 TNU• Reactor fraction: r =1.0

• Reactor error: σr =0.0

• Exposure error – Dash: σe =0.10

– Solid: σe =0.05

– Dots: σe =0.0

• Oscillation error: σo =0.0

• All detectors 1032 p+

Δc=40-30=10 TNU

Δc=40-20=20 TNU

Δc=40-10=30 TNU

Δc=40-5=35 TNU

SLAC 8/25 64

Reactor & Exposure Error

σr & σe manageable

• Mantle: m =10 TNU• Reactor fraction: r =1.0• Reactor + exposure

error – Dash: σr = σe = 0.05

– Solid: σr = σe = 0.03

– Dots: σr = σe = 0.01

• σo = 0.0

• All detectors 1032 p+

Δc=40-30=10 TNU

Δc=40-20=20 TNU

Δc=40-10=30 TNU

Δc=40-5=35 TNU

SLAC 8/25 65