# Presentation: 565675

## A Deep Ocean Anti-Neutrino Observatory

- An Introduction to the Science Potential of
- Hanohano
***A First Step for Long Range Anti-Neutrino Monitoring ***
***Of Reactors and Weapons from the Deep Ocean***
- Presented by
- John G. Learned
*University of Hawaii at Manoa*

## Hanohano Origins

- Started as an exercise in ’03 investigating future potential for world reactor and weapons testing monitoring (see Guillian report), inspired by DTRA inquiry.
- Workshop in 1/04 concluded that such will be possible, with giant detectors, and technology just being developed.
- http://www.phys.hawaii.edu/~jgl/nacw.html
- Plan is to get experience with remote monitoring with a detector that can be built today.
- Have identified at geology & physics workshops in ’05 UH and ’06 AGU Baltimore, NOW06 Italy, NNN06 Seattle, great science which a 10 kiloton deep ocean, portable, detector can accomplish.
- UH 12/05    http://www.phys.hawaii.edu/~sdye/hnsc.html
- AGU 5/06   http://www.agu.org/meetings/sm06/sm06sessions/sm06_U41F.html
- Italy 9/06     http://www.ba.infn.it/~now2006/
- Seattle 9/06  http://neutrino.phys.washington.edu/nnn06/

- John Learned at NNN06 Seattle

- 22 September 2006

## Nuclear Monitoring Requires Enormous DetectorsSingle detector,  LE = Low Energy ~>MeV, HE = High Energy ~ >GeV

- 10 MWt

- 1GWt

*Size for 25% measurement of reactor flux, 1 yr, no background. *

**Practical now**
***(HyperK)***

**Future**

- Under water

- Surface

**Present**
***(KamLAND)***

** *****Present HE Nu Detectors (ICECUBE)***

**Proposed**
***(Hanohano)***

- 1 KT Bomb

- (Future Array)

- John Learned at NNN06 Seattle

- 22 September 2006

## 1-10 Megaton Module Not Outlandish

- 1-10 **Megaton Module Not Outlandish**

- 1-10 Megaton units similar to sizes proposed for slightly higher energy,
- and much smaller than ICECUBE under construction.

- Kamland exists

- SuperK exists

**1 km****3**** under**
** ****construction**

- Proposed Megaton Hyper-Kamiokande

- John Learned at NNN06 Seattle

- 22 September 2006

## Spinoff, Planetary Defense:Type II Supernova Early Warning

**Silicon burning during last ~2 days prior to collapse detectable from whole galaxy!**
**Sudden increase in single neutron appearance**

*Odrzywolek, et al., astro-ph/0311012*

- John Learned at NNN06 Seattle

- 22 September 2006

## Hanohano Science Outline

**Introduction to project**
**Neutrino Geophysics**
- U/Th mantle flux
- Th/U ratio
- Geo-reactor search
**Neutrino Oscillation Physics *****(new)***
- Mixing angles θ12 and θ13
- Mass squared difference Δm231
- Mass hierarchy
**Other Physics, Long range, Conclusions**

- John Learned at NNN06 Seattle

- 22 September 2006

## Hanohano - 10x “KamLAND” in Ocean

**Hanohano - 10x “KamLAND” in Ocean**

**Construct in shipyard, fill/test in port, tow to site, and submerge to ~4 km**

- John Learned at NNN06 Seattle

- 22 September 2006

## Hawaii Anti-Neutrino Observatory†

- Location flexibility
- Tow to various locations, cable connect
- Far from continental crust and reactors for neutrino geophysics- Hawaii, South Pacific, ...
- Offshore of reactor for neutrino oscillation physics- California, Taiwan, ...
- †* **hanohano- *Hawaiian for distinguished

- *

- Site survey done

- John Learned at NNN06 Seattle

- 22 September 2006

## Technological issues being addressed

- Radiopurity technology   exists
- Scintillating oil studies: P=450 atm., T=0o
- Several choices available, safe, industrial
- Implosion studies at sea
- Engineering studies of detector structure, deployment

- John Learned at NNN06 Seattle

- 22 September 2006

## Actual Accomplishments: Structure

- Goal:  workable vehicle at standard ship costs.
- Analyzed stability, weight, and structural strength vs scintillator volume, 5-120kT.
- harbor, loading, testing, towing, submergence, landing, lift off, resurface, recovery.
- Single vehicle has problems with stability and weight, particularly larger sizes – Al is costly option.
- Shape is cylindrical, cube not constructable, 30m dia.
- Dual barge and detector module has much less weight and stability restrictions. Can build very large.
- 10kt Scintillator is nominal 22kT detector, lose ~0.9kT buoyancy on bottom. Ascent 46 min.
- Structure: $22m - OK

- 1/50 scale model test

- John Learned at NNN06 Seattle

- 22 September 2006

## Actual Accomplishments: Photomultiplier Electronics

- Completed electronics prototypes:
- PMT voltage supply manufacturers surveyed, sample devices in hand, several choices available (used in South Pole and Mediterranean experiments).
- PMT signal electronics prototypes constructed and tested at UH electronics facility, ready for second round for ocean tests.
- Signal digitization electronics prototypes constructed and tested at UH, ready for second round.
- No stoppers, power is as expected, need further refinement, reliability testing, etc.  Adequate for proposal stage with predictable costing at this time.

- John Learned at NNN06 Seattle

- 22 September 2006

## Geology: Big Questions

- What drives continental drift, mid-ocean seafloor spreading?
- What produces and sustains the geomagnetic field?
- How did the earth form?
- Of what is the deep earth composed?
- ► This experiment addresses all these.

- John Learned at NNN06 Seattle

- 22 September 2006

## Preliminary Reference Earth Model

*Knowledge of Earth interior from seismology*

- Dziewonski and Anderson, *Physics of the Earth and Planetary Interiors ***25 **(1981) 297-356.

- Measure velocity, use eq’n of state to infer density, guess composition.

- John Learned at NNN06 Seattle

- 22 September 2006

## Bulk Silicate Earth modelgeologists “standard model”

- Knowledge of Earth composition
- largely model dependent

- McDonough and Sun, *Chemical Geology* **120** (1995) 223-253.

- Mostly composition from three meteorites.

- John Learned at NNN06 Seattle

- 22 September 2006

## Terrestrial Heat Flow: 31-44 TW

- Hofmeister and Criss, *Tectonophysics* **395** (2005) 159-177.

- Pollack, Hurter, and Johnson, *Reviews of Geophysics**** *****31**(3)* *(1993)* *267-280.

- Varies greatly, ocean
- spreading zones a problem

- Time dependence a
- problem for geomagnetism

- John Learned at NNN06 Seattle

- 22 September 2006

## Parent Spectrum Geo-Neutrinos

- thorium chain

- uranium chain

- Threshold for Reines and Cowan
- coincidence technique

- prompt

- delayed

- No present method for K nus.

- John Learned at NNN06 Seattle

- 22 September 2006

## Predicted Geo-Neutrino Signal

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

**Borexino**

**SNO+**

**KamLAND**

**Hanohano**

- Continental locations dominated by local crustal radioactivity.

- Also LENA, EARTH,
- Baksan... proposals

- John Learned at NNN06 Seattle

- 22 September 2006

## Geo-ν + Background Spectra

**cosmic ray muons**

**alpha  source**

**radioactive materials**

**fast neutrons**

**spallation**
**products**

**Target**
**Volume**

- μ±

- μ±

- John Learned at NNN06 Seattle

- 22 September 2006

## Hanohano: Mantle/Core Measurement

**Hanohano: Mantle/Core Measurement**

**15 years of SNO+**

**48 years of Borexino**

**1 year of Hanohano**

- Must subtract uncertain crust flux to get that due to mantle/core.

- John Learned at NNN06 Seattle

- 22 September 2006

## Hanohano: Mantle Measurement

- Mantle (ev / 10 kT-y)

**No continental detector can measure **
**the mantle/core flux to better than 50% **
**due to 20% uncertainty in crust flux**

- 10 kT-yr exposure at each location

- John Learned at NNN06 Seattle

- 22 September 2006

## Earth Th/U Ratio Measurement

| Project 
crust type | δR/R
(1 yr exposure) | Th/U
(1 yr exposure) | Years to 10%
measurement |
| --- | --- | --- | --- |
| KamLAND
island arc | 2.0 |  4 ± 8
 | 390 |
| Borexino
continental | 1.1 | 4 ± 4 | 120 |
| SNO+
continental | 0.62 | 3.9 ± 2.4
 | 39 |
| Hanohano
oceanic | 0.20 | 3.9 ± 0.8
 | 3.9 |

**Statistical uncertainties only; includes reactors.**

- John Learned at NNN06 Seattle

- 22 September 2006

## Geo-ν projects: Predicted Rates

| Project
crust type  | Size
(1032 free p) | Geoneutrino
(events/y) | Crust
(events/y) | Mantle
(events/y) | Reactor
(events/y) |
| --- | --- | --- | --- | --- | --- |
| KamLAND
island arc | 0.35 | 12.5 | 9.2 | 3.3 | 83.7 |
| Borexino
continental | 0.18 | 7.6 | 5.9 | 1.7 | 6.2 |
| SNO+
continental | 0.57 | 30.0 | 24.7 | 5.3 | 35.1 |
| Hanohano
oceanic | 8.7 | 112.2 | 31.3 | 80.9 | 12.2 |

- John Learned at NNN06 Seattle

- 22 September 2006

## Measuring the Mantle

|  | Rate (10 kT-y)-1 |  |  |  |
| --- | --- | --- | --- | --- |
| Source | KamLAND | SNO+ | Borexino | Hanohano |
|  Envir. Bkgd. | 831 ± 196 | 18 ± 2 | 19 ± 2 | 12 ± 2 |
|  Reactor ν | 1434 ± 129 | 438 ± 39 | 298 ± 27 | 12 ± 1 |
|  Crust ν | 229 ± 46 | 377 ± 75 | 285 ± 57 | 30 ± 6 |
| Non-Mantle | 2494 ± 239 | 833 ± 83 | 602 ± 63 | 54 ± 7 |
| Mantle | 80 ± 16 | 80 ± 16 | 80 ± 16 | 80 ± 16 |
| Total | 2574 ± 240 | 913 ± 86 | 682 ± 65 | 134 ± 17 |
| Signal | 80 ± 290 | 80 ± 117 | 80 ± 89 | 80 ± 19 |

- Note: while continental locations cannot measure mantle,
- combined measurements from all yield important geophysics.

- John Learned at NNN06 Seattle

- 22 September 2006

## Simulated Geo-Neutrino Source 

- Weighted heavily towards local region of mantle.

- Make observations at several sites to test mantle variation.

- John Learned at NNN06 Seattle

- 22 September 2006

## Anti-Neutrinos from the Core?

**Geo-reactor hypothesis**

- Herndon hypothesis: natural breeder reactor in core of Earth with P=1-10 TW

- Herndon, *Proc. Nat. Acad. Sci.* **93** (1996) 646.
- Hollenbach and Herndon, *Proc. Nat. Acad. Sci.* **98** (2001) 11085.

- Controversial but apparently not ruled out, and if true of tremendous importance.

- John Learned at NNN06 Seattle

- 22 September 2006

## Geo-Reactor Search

**Geo-Reactor Search**

| Project 
crust type | Power limit 99% CL (TW) | 5σ discovery power
(TW) |
| --- | --- | --- |
| KamLAND
island arc | 22 | 51 |
| Borexino
continental | 12 | 43 |
| SNO+
continental | 9 | 22 |
| Hanohano
oceanic | 0.3 | 1.0 |

**1 year run time- statistical uncertainties only**

- Power upper limit

- Geo-reactor power (TW)

- Need 1 – 10 TW to drive geomagnetic field.

- John Learned at NNN06 Seattle

- 22 September 2006

## Physics Big Questions: Neutrino Properties

- Non-zero neutrino mass and oscillations between flavors established.
- Filling in MNS-P mixing matrix needed.
- Need precise (few %) values.
- Quest for θ13, need various approaches.
- Hierarchy of masses? (m1<m2<m3 ?)
- CP violation?  CPT?
- Importance to cosmology, grand unification....
- ► This experiment addresses many of these

- John Learned at NNN06 Seattle

- 22 September 2006

## Pee=1-{ cos4(θ13) sin2(2θ12) [1-cos(Δm221L/2E)]
          + cos2(θ12) sin2(2θ13) [1-cos(Δm231L/2E)]
          + sin2(θ12) sin2(2θ13) [1-cos(Δm232L/2E)]}/2

→ Each of 3 amplitudes cycles (in L/E ~ “t”) 
     with own periodicity (Δm2 ~ “ω”)
  - amplitudes 13.5 : 2.5 : 1.0 above
  - wavelengths ~110 km and ~4 km at reactor peak ~3.5 MeV

1⁄2-cycle measurements can yield
Mixing angles, mass-squared differences
Multi-cycle measurements can yield
Mixing angles, precise mass-squared differences
Potential for mass hierarchy
Less sensitivity to systematics

-           + cos2(θ12) sin2(2θ13) [1-cos(Δm2**31**L/2E)]
-           + sin2(θ12) sin2(2θ13) [1-cos(Δm2**32**L/2E)]}/2
- → Each of 3 amplitudes cycles (in L/E ~ “t”)
-      with own periodicity (Δm2 ~ “ω”)
-   - amplitudes *13.5 : 2.5 : 1.0* above
-   - wavelengths ~110 km and ~4 km at reactor peak ~3.5 MeV
- 1⁄2-cycle measurements can yield
- Mixing angles, mass-squared differences
- Multi-cycle measurements can yield
- Mixing angles, precise mass-squared differences
- Potential for mass hierarchy
- Less sensitivity to systematics

**3-****ν**** Mixing: Reactor Neutrinos**

- }  wavelength
-       close, 3%

- John Learned at NNN06 Seattle

- 22 September 2006

## Reactor & Atmospheric  ν Mixing Parameters: Present Knowledge

- KamLAND combined analysis
- 	**tan****2****(****θ****12****)****=****0.40(****+****0.10/****–****0.07)**
- 	**Δ****m****2****21****=(7.9****±****0.7)****×****10****-5**** eV****2**
- 	Araki et al., *Phys. Rev. Lett. ***94** (2005) 081801.
- CHOOZ limit **sin****2****(2****θ****13****) ****≤ ****0.20**
- 	Apollonio et al., *Eur. Phys. J. ***C27** (2003) 331-374.
- SuperK (and K2K)
- 	 **Δ****m****2****31****=(2.5****±****0.5)****×****10****-3**** eV****2**
- 	Ashie et al., *Phys. Rev. ***D64** (2005) 112005
- 	Aliu et al., *Phys. Rev. Lett. ***94** (2005) 081802

- John Learned at NNN06 Seattle

- 22 September 2006

**Notes:**
sin2(2θ12)=0.82 ± 0.07;  θ13 ≤ 13°; 0.90 ≤ cos4(θ13) ≤ 1.00

## Significant νe Flux Measurement Uncertainty Due to Oscillations

- Flux from distant, extended source like Earth or sun is fully mixed
- P(νe→νe) =1-0.5{cos4(θ13)sin2(2θ12)+sin2(2θ13)}
- 		           = 0.592 (+0.035/-0.091)
- 	Lower value for maximum angles
- 	Upper value for minimum angles
- Φsource= Φdetector/P(νe→νe)
- 	Uncertainty is +15%/-6%
-  precise flux measures need θ**12** & θ**13**

- John Learned at NNN06 Seattle

- 22 September 2006

## Proposed 1⁄2-cycle θ13 Measurements

- Reactor experiment- νe point source
- Double Chooz, Daya Bay, Reno
- θ13 with “identical” detectors
-      near (100m)/far(1-2 km)
- P(νe→νe) ≈1 -
-           sin2(2θ13)sin2(Δm231L/4E)
- sin2(2θ13) ≤ 0.03-0.01 in few years
- Solar angle & matter insensitive
- Systematics difficult

*Anderson, et al., hep-ex/0402041*

*Idea: L. Mikaelyan, V. Sinev, Phys. At. Nucl. 62 (1999) 2008, hep-ph/9811228.*

- John Learned at NNN06 Seattle

- 22 September 2006

## Suggested 1⁄2-cycle θ12 Measurement

- Reactor experiment: νe point source at modest distance (10-100 km).
- P(νe→νe)≈1-sin2(2θ12)sin2(Δm221L/4E)
- 60 GW·kT·y exposure at 50-70 km ->
- ~4% systematic error from near detector
- sin2(θ12) measured with ~2% uncertainty
*We can do job without near monitor (?)*

- Bandyopadhyay et al., *Phys. Rev. *D**67** (2003) 113011.
- Minakata et al., hep-ph/0407326
- Bandyopadhyay et al., hep-ph/0410283

- John Learned at NNN06 Seattle

- 22 September 2006

## Energy Spectra, Distance and Oscillations

- 50 km study

- Constant L/E

- First return of
- “solar” oscillation

- Log(Rate) vs Energy and DIstance

- E

- L

- John Learned at NNN06 Seattle

- 22 September 2006

## Reactor Anti-Neutrino Spectra at 50 km

**Reactor Anti-Neutrino Spectra at 50 km**

**1,2 oscillations with sin****2****(2****θ****12****)=0.82 and ****Δ****m****2****21****=7.9x10****-5**** ****eV****2**
**1,3 oscillations with sin****2****(2****θ****13****)=0.10 and**** ****Δ****m*****2*****31****=2.5x10****-3**** eV****2**

- no oscillation

- oscillations

- no oscillation

- oscillations

- Neutrino energy (MeV)

- L/E (km/MeV)

**Distance/energy, **
**L/E**

**Energy, E**

*> 15 cycles*

- suggests using Fourier Transforms

- John Learned at NNN06 Seattle

- 22 September 2006

## Rate versus Distance and θ13 

- No osc

- Osc

- Max suppression
- near 57 km

***Note shift in total rate due to ******θ******13****** ***

- Rate versus Distance

- Rate Variation with θ13

- sin2(2θ13)

- Message:
-  cannot  measure θ12
- well without
- measuring θ13.

- John Learned at NNN06 Seattle

- 22 September 2006

## Fourier Transform on L/E to Δm2

- Fourier Power, Log Scale

- Spectrum w/ θ13=0

- Δm2/eV2

*Preliminary-*
- 50 kt-y exposure at 50 km range
- sin2(2θ13)≥0.02* *
- Δm231=0.0025 eV2 to 1% level
- Learned, Pakvasa, Svoboda, Dye *preprint in preparation*

- Δm232 < Δm231
- normal** **hierarchy

**Δ****m****2**** (x10****-2**** eV****2****)**

- 0.0025 eV2 peak due to
- nonzero θ13

- Includes energy smearing

- Peak profile versus distance

- E smearing

- Fewer cycles

- 50 km

- John Learned at NNN06 Seattle

- 22 September 2006

## Beauty of Employing Fourier(new realization, by us anyway)

- Normal statistical sqrt(n) Poisson errors apply to peak amplitude (mixing angle),
- but NOT to peak location... allows possibility for very precise measurement of Δm2 (<1%?)
- Beats χ2 and normal Max£, I think. (?)
- Employ signal processing tricks to maximize information extraction (ie. matched filter).

- John Learned at NNN06 Seattle

- 22 September 2006

## Neutrino Mass Hierarchy w/ Reactor Neutrinos ?-needs work

**Neutrino Mass Hierarchy w/ Reactor Neutrinos ?**-needs work

- m3

- m3

- m2

- m1

- m1

- m2

- normal

- inverted

**|****Δ*****m*****2****31****| ****>**** |****Δ*****m*****2****32****|**

**|****Δ*****m*****2****31****| ****<**** |****Δ*****m*****2****32****|**

- mass

- Δm232 ≈ (1±0.03)Δm231

*Petcov and Piai, Phys. Lett. B****533**** (2001) 94-106.*

- Normal and
-  inverted hierarchy

- FT Pwr

- very slight
- asymmetry

**Peak has low-side small shoulder, **
**inv hierarchy shoulder on high-side.**

- John Learned at NNN06 Seattle

- 22 September 2006

## Hanohano - Candidate Reactor Sites

- SW of San Onofre, **Calif**- ~6 GWth
- SE of Maanshan, **Taiwan**- ~5 GWth

- Depth profiles

- John Learned at NNN06 Seattle

- 22 September 2006

## Hanohano Science Summary 1 Yr, 10 Kiloton Exposures

**Neutrino Geophysics, deep mid-ocean**
- Mantle flux U/Th geo-neutrinos to ~25%
- Measure Th/U ratio to ~20%
- Rule out geo-reactor of P>0.3 TW
**Neutrino Particle Physics, 50 km from reactor**
- Measure sin2 (θ12) to few % w/ standard 1⁄2-cycle
- Measure sin2(2θ13) down to ~0.05 w/ multi-cycle
- Δm231 at percent level w/ multi-cycle
-  No near detector; insensitive to background, systematics; complimentary to DC, DB, Minos, Nova
- Potential for mass hierarchy with large exposure

- John Learned at NNN06 Seattle

- 22 September 2006

## Tests & Studies Needed

- Complete module anti-implosion work/tests.
- Demonstrate optical modules and scintillator in deep ocean.
- More scintillator studies, radiopurity, optimize choice.
- Further detector barge design and full costing.
- More detailed geological simulation, error analysis and study choice of deep ocean sites.
- Reactor distance and depth, including backgrounds.
- Can we do neutrino mass hierarchy with FT method?
- Neutrino direction studies.
- + Other physics: SN, relic SN, nucleon decay, ... *(recall that this will be the largest low energy detector, 20x KamLAND, 10x SNO+, 50x Borexino, but 0.2x LENA?*).

- John Learned at NNN06 Seattle

- 22 September 2006

## First step in development of long range neutrino monitoring applications
Hanohano
10 kT deep ocean anti-neutrino observatory
Movable for multi-disciplinary science
Neutrino geophysics
Neutrino oscillation physics and more
Under development at Hawaii 
1st collaboration meeting 3/07 in Hawaii
interested? jgl@phys.hawaii.edu

Acknowledgements: Steve Dye, Peter Grach,  Shige Matsuno, Sandip Pakvasa, Joe Van Ryzin, Bob Svoboda, Gary Varner, Mavourneen Wilcox, Makai Ocean Engineering, CEROS, DOE, UHM

- Hanohano
- 10 kT deep ocean anti-neutrino observatory
- Movable for multi-disciplinary science
- Neutrino geophysics
- Neutrino oscillation physics and more
- Under development at Hawaii
- 1st collaboration meeting 3/07 in Hawaii
*interested? jgl@phys.hawaii.edu*
- Acknowledgements: Steve Dye, Peter Grach,  Shige Matsuno, Sandip Pakvasa, Joe Van Ryzin, Bob Svoboda, Gary Varner, Mavourneen Wilcox, Makai Ocean Engineering, CEROS, DOE, UHM

**Conclusion**

- John Learned at NNN06 Seattle

- 22 September 2006

## backups

- John Learned at NNN06 Seattle

- 22 September 2006

## Nucleon Decay with Hanohano

- PDK and SN data with geophysics studies...
- Nucleon Decay: kaon modes:
- present:      **τ****/**b > 2.3 x 10**33** y *[Super-K, PR D ****72****, 052007 (2005)].*
- Hanohano: **τ****/**b > 10**34** y  with 10 yr *[Lena PR D 72, 075014** **(2005)]*
- Neutron Disappearance:
- present:**      ****τ**(n  → invis) > 5.8 × 10**29**y at 90% CL
**      ****τ**(nn → invis) > 1.4 × 10**30**y at 90% CL
-     *[838 & 1119 metric ton-years of  KamLAND, PRL 96 (2006) 101802] *
- Hanohano: **τ**(n  → invis) > 5 x 10**31** y at 90% CL  10 yrs
**     ****τ**(nn → invis) > 5 x 10**31 **y at 90% CL

*Simulations needed*

- John Learned at NNN06 Seattle

- 22 September 2006