John Learned Univ. of Hawaii

1. JGL at Geonu 2013 John Learned Univ. of Hawaii Future Large Liquid Scintillator Experiments For Geonu Studies and Much More Presentation at Neutrino Geosciences, Takayama, 23 March 2013

2. John Learned at Cornell Nuclear Reactors (power stations, ships)  Sun  Particle Accelerator  Supernovae (star collapse) SN 1987A  Earth’s Atmosphere (Cosmic Rays)  Astrophysical Accelerators Soon ? Big Bang (here 330 /cm3) Indirect Evidence Where do Neutrinos come from?We can study most of these with a deep ocean instrument!  Earth’s Composition (Natural Radioactivity)

3. JGL at Geonu 2013 Why this is a wide interest project • A large deep underwater detector can address almost all of these neutrino sources! • Many of them simultaneously. Low and high energy searches do not interfere. Nor do searches for rare phenomena such as supernovae and proton decay. • Such an instrument is not just one experiment yielding one number, but will supply a huge variety of results (and PhDs) and can engage a large scientific community. • This is true in geology as well as particle physics and astrophysics

4. JGL at Geonu 2013 Geology Involvement • Studies to decide on locations for detector: • Ocean bottom cores, region studies • Development of pile and other models • Best possible regional calculations • Studies on spectra expected: • Close examination of U/Th decay chains and beta decays • Pressure effects? • Improvement of earth models: • Tuning various models with working groups • Crucial temperature and seismic studies in less know regions? • Sharpening community focus on earth heat issues • Engaging the whole Geo Community in a project touching many specialities • Seeking lateral variation and possible explanations, hidden reservoirs • We need a large multidisciplinary team to put this all together, not just physicists.

5. JGL at Geonu 2013 The Road to Geonu Science Know we need great mass detectors > kiloton scale -> megaton scale Only (presently) viable technology is large tanks of liquid scintillator Difficult to resolve mantle from crust at continental locations Best to be far from nuclear reactors = mid-ocean Need to be deep to avoid background (>3km) Ocean offers potential for relocation to multiple sites We can start with what we have now, all technology exists Challenges to do even better and go further than just “local” geonu rate: Better scintillator (output, water based, attenuation length) New optical detectors, better coverage and time resolution Directionality? K40 nus from the earth?

6. JGL at Geonu 2013 Large Electron Anti-Neutrino Experiments* • Continuing Experiments • KamLAND 1 kT LS 2 kmwe 1 MeV • Borexino 0.4 kT LS 3 kmwe 1 MeV • Near Term • SNO+ 1kT LS+ 4 kmwe 1 MeV • SK (w/Gd?) 22kT H2O+Gd 2 kmwe 4 MeV • Proposed • HyperK 600kT H2O+? 1.5 kmwe(?) 6 MeV • DayaBay2 20kT LS 1.5kmwe 1 MeV • RENO50 5kT LS ? kmwe 1 MeV • LENA 50kT LS 3 kmwe 1 MeV • LBNE Homestake 17kT Lar 0 or 4 kmwe 100 MeV? • Watchman 1kT H2O+Gd 0.3 kmwe 4 MeV • Hanohano 10kT LS 2-5 kmwe 1 MeV *Neglecting MINOS and NOVA, INO and MiniBOONE detectors, not relevant to this discussion on MeV electron anti-neutrinos. (And also to keep the list manageable… herein.)

7. JGL at Geonu 2013 Rough Physics Domains of Large Nuebar Experiments * Assuming 37 kT and deep

8. John Learned at Cornell Locations for Present & Possible Geonu Experiments SNO+ LENA Baksan LBNE LAr Hanohano Kamland SuperK HyperK DayaBay2 EARTH ? Borexino Color indicates U/Th neutrino flux, mostly from crust

9. John Learned at Cornell Simulated Geoneutrino Origination Points 50% within 500km25% from Mantle KamLAND In Mid-Ocean 70% Mantle 30% Other Assumes homogeneous mantle & no core source SanshiroEnomoto

10. John Learned at Cornell Why we need Geonu measuements in the deep ocean to measure the Mantle Contribution Crust Only Mantle Models 16-18 typical 12-39 extreme mantle Steve Dye

11. John Learned at Cornell With a deep ocean detector we could resolve aSingle Reactor Source at CMB resolution to few km 10 sample simulated 1 yr runs 1 GW source observed by 100 kT detector can be cleaned up

12. John Learned at Cornell What Next for Geonus? • Measure gross fluxes from crust and mantle • Discover or set limits on georeactors. • Better earth models • Explore lateral homogeneity • Use directionality for earth neutrino tomography • Follow the science….

13. JGL at Geonu 2013 Applied Neutrinos!Program to Study Long Range Reactor Monitoring and Detection • Working with colleagues at UH, NGA and IAI in US. • Studies using all available neutrino tools: • Hypothetical large detectors (100kT class) • Assume availability of new photodetectors (LAPPDS of the like) • Use oscillations fully in analysis • Calculate full backgrounds including earth model and detector depth • Use full Max Liklihood, with Bayesian statistics • Test importance of directional detection (obvious answer: very big boost) • Conclusions: Works better than we had guessed… big paper in press in Physics Reports. Will show some pictures here.

14. JGL at Geonu 2013 mTC Idea First, testing out new technology for precise antineutrino detection at UH • Do imaging with (100 ps) fast timing, not optics (time reversal imaging). • Small portable 2.2 liter scintillating cube, • Boron doped plastic. • 4 x 6 MCP (x64 pixels each) fast pixel detectors on surrounding faces • Get neutrino directionality. • Reject noise on the fly. • ~10/day anti-neutrino interactions (inverse beta decay signature) from power reactor (San Onofre). 13 cm 2.2 liter

15. JGL at Geonu 2013 mTC Virtues • Small size avoids positron annihilation gammas which • smear resolution (Xo ~42 cm).... gammas mostly escape, • permitting precise positron creation point location. • Fast pixel timing (<100ps) and fast pipeline processing of • waveforms rejects background in real time. • Having many pixels plus use of first-in light permits mm precision in vertex locations. • Neutrino directionality via precision positron production • and neutron absorption locations. • No need for shielding (unlike other detectors, • except very close to reactor • Feasible even in high noise environment, near reactor • vessel, at surface (eg. in a truck). • Plan to take to reactor summer 2013

16. JGL at Geonu 2013 Snapshot of the Fermat Surface for a Single Muon-likeTrack Track Huygens wavelets Incoherent sum coincident with Cherenkov surface: Not polarized! J. Learned arXiv:0902.4009v1

17. JGL at Geonu 2013 Time Reversal Image Reconstruction Figure by Mich Sakai

18. JGL at Geonu 2013

19. JGL at Geonu 2013

20. JGL at Geonu 2013 Fitting the Positron Streak

21. JGL at Geonu 2013

22. JGL at Geonu 2013 Reactor Rate versus Range • 66 kT water based • detector, no cuts. • 300 MWth Reactor

23. JGL at Geonu 2013 Where the Reactors Live

24. JGL at Geonu 2013 Table of Backgrounds & Rates Lasserre and friends

25. JGL at Geonu 2013 Smart integration of geonus illustration

26. JGL at Geonu 2013 Crust and Mantle versus Range

27. JGL at Geonu 2013 Where Comes the Geonus? • Account for oscillations and energy smearing One lesson of the study: oscillations are very important tool. NUDAR

28. JGL at Geonu 2013 Geonu and Reactor Spectralocation off Spain ~300km to nearest reactor Geonus rule!

29. JGL at Geonu 2013 Seeking a Reactor: Where Comes the Background? Sum of backgrounds Spectrum of backgrounds

30. JGL at Geonu 2013

31. JGL at Geonu 2013 Finding a Reactor and Power Output

32. John Learned at Cornell Future Geonu Dreams: Directional Sensitivity Directional information provides: ・Rejection of backgrounds ・Separation of crust and mantle ・Earth tomography by multiple detectors Good News: ・Recoiled neutron remembers direction Bad News: ・Thermalization blurs the info ・Gamma diffusion spoils the info ・Reconstruction resolution is too poor Wish List: ・large neutron capture cross-section ・(heavy) charged particle emission & ・good resolution detector (~1cm)

33. JGL at Geonu 2013 Increased angular resolution buys a lot

34. John Learned at Cornell Hanohanoa mobile deep ocean detector Measure electron antinus for: Geophysics Particle physics (hierarchy, mixing parameters) Remote reactor monitoring for anti-proliferation. And lots more science… Results from DARPA funded study, employing Makai Ocean Engineering for preliminary design and feasibility study. 10 kiloton liquid scintillation Up to ~100 kt possible Deploy and retrieve from barge

35. John Learned at Cornell Hanohano Engineering StudiesMakai Ocean Engineering • Studied vessel design up to 100 kilotons, based upon cost, stability, and construction ease. • Construct in shipyard • Fill/test in port • Tow to site, can traverse Panama Canal • Deploy ~4-5 km depth • Recover, repair or relocate, and redeploy Barge 112 m long x 23.3 wide Deployment Sketch Descent/ascent 39 min

36. John Learned at Cornell Addressing Technology Issues 20m x 35m fiducial vol. • Scintillating oil studies in lab • P=450 atm, T=0°C • Testing PC, PXE, LAB and dodecane • No problems so far, LAB favorite… optimization needed • Implosion studies • Design with energy absorption • Computer modeling & at sea • No stoppers • Power and comm, no problems • Optical detector, prototypes OK • Need second round design 1 m oil 2m pure water

37. John Learned at Cornell 2 Candidate Off-shore Nuclear Power Reactor Sites for Physics San Onofre, California- ~6 GWth Maanshan, Taiwan- ~5 GWth Can do unique studies of neutrino properties 50-60 km out from reactors.

38. John Learned at Cornell Summary of Expected ResultsHanohano- 10 kt-1 yr Exposure • Neutrino Geophysics- near Hawaii • Mantle flux U geoneutrinos to ~10% • Heat flux ~15% • Measure Th/U ratio to ~20% • Rule out geo-reactor if P>0.3 TW • Neutrino Oscillation Physics- ~55 km from reactor • Measure sin2 (θ12) to few % w/ standard ½-cycle • Measure sin2(2θ13) down to ~0.05 w/ multi-cycle • Δm231 to less than 1% w/ multi-cycle • Mass hierarchy w/multi-cycle & no near detector; insensitive to background, systematic errors; complementary to Minos, Nova • Much other astrophysics and nucleon decay too….

39. John Learned at Cornell Additional Physics/Astrophysics Hanohano will be biggest low energy neutrino detector (except for maybe LENA) • Supernova Detection: special νe ability • Relic SN Neutrinos • GRBs and other rare impulsive sources • Exotic objects (monopoles, quark nuggets, etc.) • Long list of ancillary, non-interfering science, with strong discovery potential Broad gauge science and technology, a program not just a single experiment.

40. JGL at Geonu 2013 Other Applications for a large deep-water neutrino detector • Long Baseline with accelerators ~ 1 GeV • Hanohano with Tokai Beam (between Japan and Korea)? • LENA with CERN beam?? • New LBNE Experiment with Fermilab Beam?? • Nucleon Decay (high free proton content) • view details of decays such as Kaon modes • Particle Astrophysics (low mass WIMPS,…) • + All the low energy physics (geonus, reactor studies, monitoring, solar neutrinos…..) unimpeded!

41. JGL at Geonu 2013 What now? • We are ready to plan for a large deep ocean neutrino detector • To study geology • And much else • We need a large interdisciplinary and multinational team to pull this off • Many areas of expertise needed • Please consider how you can help