“ georeactor ” detection with gigaton antineutrino detectors

““Georeactor” Detection with GGeoreactor” Detection with Gigaton Antineutrino Detectorsigaton Antineutrino Detectors

Neutrinos and Arms Control WorkshopNeutrinos and Arms Control Workshop

February 5, 2004February 5, 2004

Eugene GuillianEugene Guillian

University of HawaiiUniversity of Hawaii

Finding Hidden Nuclear ReactFinding Hidden Nuclear Reactorsors

The focus of this conference is on detectinThe focus of this conference is on detecting hidden man-made nuclear reactorsg hidden man-made nuclear reactors

But there may be a But there may be a natural nuclear reactnatural nuclear reactor hidden in the Earth‘s core!or hidden in the Earth‘s core!

The “Georeactor” ModelThe “Georeactor” Model

An unorthodox modelAn unorthodox model Chief proponent: Chief proponent: J.M.HerndonJ.M.Herndon

The modelThe model A fuel breeder fission reactor in the Earth‘s suA fuel breeder fission reactor in the Earth‘s su

b-coreb-core Size:Size: ~4 miles radius ~4 miles radius Power:Power: 3-10 TW 3-10 TW

Man-made vs. GeoMan-made vs. Geo

Man-made:Man-made: (~500 reactors) x (~2 GW) = (~500 reactors) x (~2 GW) = 1 TW1 TW

Georeactor:Georeactor: 3-10 TW3-10 TW

If a georeactor exists, it will be the dominant source of antineutrinos!

Outline of PresentationOutline of Presentation

1.1. Georeactor detection strategyGeoreactor detection strategy

2.2. Describe the georeactor modelDescribe the georeactor model

3.3. Can a georeactor be detected with KamLCan a georeactor be detected with KamLAND?AND?

4.4. What minimum conditions are necessary What minimum conditions are necessary to detect a georeactor?to detect a georeactor?

Strategy for Georeactor DetecStrategy for Georeactor Detectiontion

If a georeactor does If a georeactor does notnot exist… exist…

• From commercial power plants• Depends on the net power output• Rate corrected to 100% livetime & efficiency• Assume no neutrino oscillation

• Corrected to 100% livetime & efficiency• Neutrino oscillation effect included

Slope = average neutrino oscillation survival probability

<R> = Average

2f = Spread

<R> = Average

f = Spread

Rmin = (1-f)<R>

Rmax = (1+f)<R>

Y-inercept = Georeactor Rate

0

Strategy for Georeactor DetecStrategy for Georeactor Detectiontion

If a georeactor If a georeactor doesdoes exist… exist…

10 TW georeactor

Nonzero Y-intercept(0.0742 events/day @ 10 TW)

Georeactor Detection StrategGeoreactor Detection Strategyy

Plot observed rate against expected backgPlot observed rate against expected background rateround rate

Fit line through dataFit line through data Y-intercept = Y-intercept = georeactor rategeoreactor rate

The Georeactor ModelThe Georeactor Model

What we can all agree on:What we can all agree on:1.1. The Earth is made of the The Earth is made of the same stuff as metsame stuff as met

eoriteseorites

2.2. In its earliest stages, the Earth was In its earliest stages, the Earth was moltenmolten

3.3. The Earth gradually The Earth gradually cooledcooled, leaving all but t, leaving all but the outer core in solid formhe outer core in solid form

Melting a RockMelting a Rock

Very high temperature:Very high temperature: All of rock in liquid formAll of rock in liquid form

Lower temperature:Lower temperature: SlagSlag solidifies solidifies Alloys and opaque mineralsAlloys and opaque minerals still in liquid for still in liquid for

mm

Slag floatsSlag floats

Apply This Observation to the Apply This Observation to the EarthEarth

Very Hot!

All Liquid

Apply This Observation to the Apply This Observation to the EarthEarth

Cooler

Slag solidifies,Floats to surface

Fission Fuel Trapped by SlaFission Fuel Trapped by Slag?g?

Actinides (U, Th, Actinides (U, Th, etcetc.) are .) are lithophilelithophile (or ox (or oxiphile)iphile) If given a chance, they combine with slagIf given a chance, they combine with slag Slag rises to surface as the Earth coolsSlag rises to surface as the Earth cools Fission fuel found in the Earth‘s crust and maFission fuel found in the Earth‘s crust and ma

ntle, not in the corentle, not in the core Therefore, a georeactor cannot form!Therefore, a georeactor cannot form!

Fission Fuel Trapped by SlaFission Fuel Trapped by Slag?g?

Actinides (U, Th, Actinides (U, Th, etcetc.) are .) are lithophilelithophile (or ox (or oxiphile)iphile) If given a chance, they combine with slagIf given a chance, they combine with slag Slag rises to surface as the Earth coolsSlag rises to surface as the Earth cools Fission fuel found in the Earth‘s crust and maFission fuel found in the Earth‘s crust and ma

ntle, not in the corentle, not in the core Therefore, a georeactor cannot form!Therefore, a georeactor cannot form!

If there is enough oxygen

If There Were Insufficient OxyIf There Were Insufficient Oxygengen

Some of the U, Th will be in Some of the U, Th will be in alloy and sulfalloy and sulfide ide formform

These sink as the Earth coolsThese sink as the Earth cools Elements with largest atomic number shouElements with largest atomic number shou

ld sink mostld sink most Therefore, fission fuel should sink to the cTherefore, fission fuel should sink to the c

enter of the Earthenter of the Earth Georeactor can form!Georeactor can form!

How Can One Tell if the Earth How Can One Tell if the Earth Is Oxygen Poor or Not?Is Oxygen Poor or Not?

Slag has high oxygen contentSlag has high oxygen content Alloys and opaque minerals have low oxygAlloys and opaque minerals have low oxyg

en contenten content Alloy/Slag mass ratioAlloy/Slag mass ratio

Strong correlation with oxygen content in a mStrong correlation with oxygen content in a meteoriteeteorite

Oxygen Level of the EarthOxygen Level of the Earth

Oxygen Content HighLow

AlloySlag

LessSlag

MoreSlag

Meteorite Data

Ordinary Chrondite

Enstatite Chrondite



AlloySlag

LessSlag

MoreSlag

Actinidestrapped in

slag

Freeactinides



AlloySlag

LessSlag

MoreSlag

AlloySlag

CoreMantle

=



AlloySlag

LessSlag

MoreSlag

Core/Mantle ratiofrom seismic data

Measuring the Earth‘s OxidatiMeasuring the Earth‘s Oxidation Levelon Level

Equate the following:Equate the following: CoreCore alloy & opaque mineralsalloy & opaque minerals Mantle + CrustMantle + Crust silicatessilicates

Obtain Earth‘s mass ratio from density profile meObtain Earth‘s mass ratio from density profile measured with seismic dataasured with seismic data

Compare with corresponding ratio in meteorites.Compare with corresponding ratio in meteorites. Oxygen Content of the Earth:Oxygen Content of the Earth:

Same asSame as meteorite with same mass ratio as the Earthmeteorite with same mass ratio as the Earth‘s‘s

Evidence for Oxygen-poor EaEvidence for Oxygen-poor Earthrth

Herndon, J.M. (1996) Proc. Natl. Acad. Sci. USA 93, 646-648.

The EarthSeems to beOxygen-poor!

33He Evidence for GeoreactorHe Evidence for Georeactor

Fission reactors produce Fission reactors produce 33HH 33H decays to H decays to 33He (half life ~ 12 years)He (half life ~ 12 years)

33He MeasurementsHe Measurements

In air:In air: RRAA = = 33He/He/44He = 1.4 x 10He = 1.4 x 10-6-6

From deep Earth:From deep Earth: R ≈ 8 x RR ≈ 8 x RAA

Elevated deep Earth levels difficult to explElevated deep Earth levels difficult to explainain Primordial Primordial 33He and “Just-so” dilution scenariosHe and “Just-so” dilution scenarios

A georeactor naturally produces A georeactor naturally produces 33He…He…

… … and Just the Right Amount!and Just the Right Amount!

SCALE Reactor Simulator(Oak Ridge)

Deep Earth Measurement(mean and spread)

Fig. 1, J.M.Herndon,Proc. Nat. Acad. Sci.USA, Mar. 18, 2003(3047)

Other PhenomenaOther Phenomena

Georeactor as a Georeactor as a fluctuatingfluctuating energy sourc energy source for geomagnetisme for geomagnetism

3 of the 4 gas giants 3 of the 4 gas giants radiate twice as muradiate twice as much heat as they receivech heat as they receive

OkloOklo natural fission reactor (remnant) natural fission reactor (remnant)

Can a Georeactor Be DetecteCan a Georeactor Be Detected with KamLAND?d with KamLAND?

KamLANDKamLAND A 0.4 kton antineutrino detectorA 0.4 kton antineutrino detector Currently, the largest such detector in the worlCurrently, the largest such detector in the worl

dd

2-parameter fit2-parameter fit Slope (constrained)Slope (constrained) Y-intercept (unconstrained)Y-intercept (unconstrained)



dd


Solar neutrinoexperiments



dd


Georeactor Rate

Measuring the Georeactor RatMeasuring the Georeactor Rate with KamLANDe with KamLAND

Slope constrained by solar neutrino measurements

Slope ≈ 0.75 ± 0.15

Georeactor rate

Large BackgroundLarge Background

Background

Signal

S/B ≈ 1/3 ~ 1/8

Slope UncertaintySlope Uncertainty

1 uncertainty in solar neutrino oscillation parameters (m2, sin22)(rough estimate)

Best fit

Can a Georeactor be DetecteCan a Georeactor be Detected?d?

Use Use Error EllipseError Ellipse to answer this question to answer this question

Ellipse EquationEllipse Equation


Measured georeactore rate

(y-intercept)

True georeactore rate

Distance of measuredrate from true value


Mueasured slope Best estimate of slope(from solar experiments)

Distance of measuredslope from best estimate


Correlation between slopeand rate measurements

Ellipse EquationEllipse EquationConfidence level

of fit result


Ellipse Parameters

They determine the size of the ellipse


Ellipse Parameters

RRgg Georeactor rateGeoreactor rate

TT Exposure timeExposure time

<R><R> Average background rateAverage background rate

ff Spread in background rateSpread in background rate

mm Slope uncertaintySlope uncertainty

Parametersdepend on

Ellipse ParametersEllipse Parameters<R> = average background rate f = fractional spread of background rate T = Exposure time Rg = georeactor ratem = oscillation probability uncertainty m0 = 0.75

Error Ellipse for KamLAND, Error Ellipse for KamLAND, 3 Years3 Years

<R> ≈ 0.62 events/day<R> ≈ 0.62 events/day f ≈ 16% f ≈ 16% ((i.e.i.e. RMS(R)/<R> = 0.16) RMS(R)/<R> = 0.16)

T = 3 years T = 3 years (12% down time fraction not included)(12% down time fraction not included)

RRgg = 0.0742 events/day = 0.0742 events/day (10 TW georeactor)(10 TW georeactor)

mm = 0.15 = 0.15 (slope uncertainty from solar (slope uncertainty from solar meas.) meas.)

mm00 = 0.75 = 0.75 (slope = avg. surv. prob.)(slope = avg. surv. prob.)

KamLAND, 3 YearsKamLAND, 3 Years

KamLAND, How Many Years?KamLAND, How Many Years?

40 years for90% confidence level!

Effect of Background SpreadEffect of Background Spread

Reducing the Background LeReducing the Background Levelvel

Slope Uncertainty ImprovemeSlope Uncertainty Improvementsnts

Detector SizeDetector Size

1 Gigaton = 2,500,000

Gigaton Detector

Go ~ 2.5 km along axis!

Gigaton Detector

Summary of ResultsSummary of Results

Georeactor will Georeactor will NOTNOT be observed with Ka be observed with KamLANDmLAND

Large spread in background rate helpsLarge spread in background rate helps Low background levelLow background level

Georeactor detectable with small detectorGeoreactor detectable with small detector


Slope uncertaintySlope uncertainty Improved knowledge helps somewhatImproved knowledge helps somewhat

A ~10A ~1022 increase in detector size allows ge increase in detector size allows georeactor detectionoreactor detection

1 Gigaton = 2.5 million x KamLAND1 Gigaton = 2.5 million x KamLAND

Most antineutrinos detected by a gigaton detector will be from the georeactor!

Event Rate @ Gigaton DetectEvent Rate @ Gigaton Detectoror

0.0742 events/day0.0742 events/day 0.4 kton0.4 kton 10 TW10 TW x 2,500,000

≈ 200,000 events/day

Expected rate from man-made reactors: 20,000 ev/day

CaveatCaveat

In this analysis, information from the antinIn this analysis, information from the antineutrino energy spectrum was not used.eutrino energy spectrum was not used.

Therefore the statement that KamLAND cTherefore the statement that KamLAND cannot say anything meaningful about a geannot say anything meaningful about a georeactor is prematureoreactor is premature Setting 90% limit may be possibleSetting 90% limit may be possible Positive identification, however, Positive identification, however, isis impossiblimpossibl

ee

ConclusionConclusion

An array of gigaton detectors whose primaAn array of gigaton detectors whose primary aim is arms control ry aim is arms control will definitely allow will definitely allow the detection of a georeactorthe detection of a georeactor (if it exists) (if it exists)

The detection of a georeactor will have giaThe detection of a georeactor will have giant repercussions on our understanding of nt repercussions on our understanding of planet formation and geophysicsplanet formation and geophysics

Evidence for Oxygen-poor EaEvidence for Oxygen-poor Earth (2)rth (2)

If we accept that the Earth was made from If we accept that the Earth was made from molten meteorites, the following mass ratiomolten meteorites, the following mass ratios must holds must hold

Mass(core) Mass(alloys, opaque minerals) =Mass(mantle) Mass(slag)

Using density profile from seismic data

Meteorite data

Evidence for Oxygen-poor EaEvidence for Oxygen-poor Earth (3)rth (3)

Herndon, J.M. (1996) Proc. Natl. Acad. Sci. USA 93, 646-648.

The EarthSeems to beOxygen-poor!

Earth‘s Interior from Earth‘s Interior from Two ModelsTwo Models

33He/He/44He from the Georeactor ModelHe from the Georeactor Model

SCALE Reactor Simulator(Oak Ridge)

Deep Earth Measurement(mean and spread)

Fig. 1, J.M.Herndon,Proc. Nat. Acad. Sci.USA, Mar. 18, 2003(3047)

Detection StrategyDetection Strategy

Background (commercial nuclear reactors)

Signal (georeactor)

Slope = average oscillation survival probability

Detection StrategyDetection Strategy

Slope constrained by solar neutrino measurements

Slope ≈ 0.75 ± 0.15

Georeactor rate


1 uncertainty in solar neutrino oscillation parameters (m2, sin22)(rough estimate)

Best fit

Measuring the Georeactor PoMeasuring the Georeactor Powerwer

Fit a line through data: Fit a line through data: observed vs. expected rateobserved vs. expected rate

xi = expected e rateyi = observed e ratei = stat. err. yi

i = bin index

b = georeactor ratem = commercial reactor e avg. survival probabilitym0 = best estimate from solar experimentsm = estimated uncertainty

Measuring the Georeactor PoMeasuring the Georeactor Powerwer

Fit a line through data: Fit a line through data: observed vs. expected rateobserved vs. expected rate

xi = expected e rateyi = observed e ratei = stat. err. yi

i = bin index

b = georeactor ratem = commercial reactor ne avg. survival probabilitym0 = best estimate from solar n experimentsm = estimated uncertainty

Measure this

Line Fit to DataLine Fit to Data

What Conditions are Necessary tWhat Conditions are Necessary to Detect a 10 TW Georeactor? o Detect a 10 TW Georeactor?

Detector sizeDetector size Signal and background scale by the same factorSignal and background scale by the same factor

Exposure timeExposure time Overall increase in statisticsOverall increase in statistics

Slope (average survival probability)Slope (average survival probability) Uncertainty that is independent of exposure timeUncertainty that is independent of exposure time Improvement over time with more/better solar Improvement over time with more/better solar meas meas

urementsurements Commercial reactor backgroundCommercial reactor background Spread in background levelSpread in background level

Error Contour FormulaError Contour Formula

Error Contour FormulaError Contour Formula<R> = average background rate f = fractional spread of background rate T = Exposure time Rg = georeactor ratem = oscillation probability uncertainty m0 = 0.75

KamLAND, 3 YearsKamLAND, 3 Years

KamLAND, How Many Years?KamLAND, How Many Years?


Improved knowledge of neutrino oscillation Improved knowledge of neutrino oscillation parameters help, but not enough to allow parameters help, but not enough to allow KamLAND to detect a georeactorKamLAND to detect a georeactor

A x100 increase in detector size will allA x100 increase in detector size will allow 99% detection of a 10TW georeactoow 99% detection of a 10TW georeactor, even under high background conditior, even under high background conditions as in KamLANDns as in KamLAND Don‘t need to go all the way to a gigaton (x20Don‘t need to go all the way to a gigaton (x20

00), although it will allow a comfortable margi00), although it will allow a comfortable marginn

“ georeactor ” detection with gigaton antineutrino detectors

Documents

georeactor detectionif

georeactor modelcan

georeactor rate0strategy

earth coolsfission fuel

earth coolselements

moltenthe earth

surfacefission fuel

earths core