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23 March 2013 Future Large Liquid Scintillator Experiments For Geonu Studies and Much More John Learned Univ. of Hawaii Presentation at Neutrino Geosciences, Takayama, 23 March 2013 JGL at Geonu 2013 1 Where do Neutrinos come from? We can study most of these with a deep ocean instrument! Nuclear Reactors (power stations, ships) Particle Accelerator Supernovae (star collapse) SN 1987A Astrophysical Accelerators Soon ? Earth’s Atmosphere (Cosmic Rays) Earth’s Composition 13 April 2009 Sun Big Bang (here 330 /cm3) Indirect Evidence (Natural Radioactivity) John Learned at Cornell 2 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 23 March 2013 JGL at Geonu 2013 3 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. 23 March 2013 JGL at Geonu 2013 4 23 March 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? JGL at Geonu 2013 5 Large Electron Anti-Neutrino Experiments* Continuing Experiments KamLAND Borexino 1 kT LS 2 kmwe 1 MeV 0.4 kT LS 3 kmwe 1 MeV 4 kmwe 1 MeV H2O+Gd 2 kmwe 4 MeV Near Term SNO+ SK (w/Gd?) 1kT 22kT LS+ Proposed HyperK 600kT H2O+? 1.5 kmwe(?) 6 MeV DayaBay2 20kT LS 1.5 kmwe 1 MeV RENO50 5kT LS ? kmwe 1 MeV 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 1 MeV LENA 2-5 kmwe *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.) 23 March 2013 JGL at Geonu 2013 6 Rough Physics Domains of Large Nuebar Experiments Physics KL BX SNO+ SK w/ HK DB2 RN50 LENA Hstk LAr* Watch Hano Reactor Mon ☻☻ ☻ ☻ ☻ ☻ ☻☻☻ ☻☻☻ ☻ ☻☻ ☻☻ ☻☻☻ Reactor Hierarchy ☻ ☻ ☻ ☻ ☻ ☻☻☻ ☻☻☻ ☻ ☻☻ ☻ ☻☻☻ Geonu Det. ☻☻ ☻☻ ☻☻ ☻ ☻ ☻ ☻ ☻☻ ☻☻ ☻ ☻☻☻ Geonu Mantle ☻ ☻ ☻ ☻ ☻ ☻ ☻ ☻ ☻☻ ☻ ☻☻☻ CR nus ☻ ☻ ☻ ☻☻ ☻☻ ☻ ☻ ☻ ☻ ☻ ☻☻ Indirect DM ☻ ☻ ☻ ☻☻ ☻☻ ☻ ☻ ☻ ☻☻ ☻ ☻☻ SN nus ☻ ☻ ☻ ☻☻☻ ☻☻☻ ☻ ☻ ☻ ☻☻ ☻ ☻☻☻ Relic SN nus ☻ ☻ ☻ ☻☻ ☻☻☻ ☻ ☻ ☻ ☻ ☻ ☻☻☻ No Nu ββ ☻☻☻ ☻ ☻☻☻ ☻ ☻ ☻ ☻ ☻ ☻ ☻ ☻ LBNE θ13 ☻? ☻ ☻ ☻☻ ☻☻ ☻ ☻ ☻ ☻☻ ☻ ☻? LBNE CPV ☻ ☻ ☻ ☻ ☻☻ ☻ ☻ ☻ ☻☻ ☻ ☻? PDK ☻ ☻ ☻ ☻☻ ☻☻☻ ☻ ☻ ☻☻☻ ☻☻ ☻ ☻☻ 23 March 2013 JGL at Geonu 2013 * Assuming 37 kT and deep 7 Locations for Present & Possible Geonu Experiments SNO+ LENA Baksan LBNE LAr Hanohano Kamland SuperK HyperK DayaBay2 EARTH ? 13 April 2009 Borexino Color indicates U/Th neutrino flux, mostly from crust John Learned at Cornell 8 Simulated Geoneutrino Origination Points KamLAND In Mid-Ocean 70% Mantle 30% Other Assumes homogeneous mantle & no core source 13 April 2009 50% within 500km 25% from Mantle John Learned at Cornell Sanshiro Enomoto 9 Why we need Geonu measuements in the deep ocean to measure the Mantle Contribution 13 April 2009 Crust Only Mantle Models 16-18 typical 12-39 extreme mantle John Learned at Cornell Steve Dye 10 With a deep ocean detector we could resolve a Single Reactor Source at CMB resolution to few km 13 April 2009 10 sample simulated 1 yr runs 1 GW source observed by 100 kT detector John Learned at Cornell can be cleaned up 11 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 April 2009 John Learned at Cornell 12 JGL at Geonu 2013 23 March 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. 13 First, testing out new technology for precise antineutrino detection at UH mTC Idea 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. 2.2 liter 23 March 2013 ~10/day anti-neutrino interactions (inverse beta decay signature) from power reactor (San Onofre). JGL at Geonu 2013 14 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 23 March 2013 JGL at Geonu 2013 15 23 March 2013 Snapshot of the Fermat Surface for a Single Muon-likeTrack Track Huygens wavelets JGL at Geonu 2013 Incoherent sum coincident with Cherenkov surface: Not polarized! J. Learned arXiv:0902.4009v1 16 23 March 2013 Time Reversal Image Reconstruction JGL at Geonu 2013 Figure by Mich Sakai 17 23 March 2013 JGL at Geonu 2013 18 23 March 2013 JGL at Geonu 2013 19 23 March 2013 Fitting the Positron Streak JGL at Geonu 2013 20 23 March 2013 JGL at Geonu 2013 21 Reactor Rate versus Range 66 kT water based detector, no cuts. 300 MWth Reactor 23 March 2013 JGL at Geonu 2013 22 23 March 2013 Where the Reactors Live JGL at Geonu 2013 23 23 March 2013 Table of Backgrounds & Rates JGL at Geonu 2013 24 23 March 2013 Smart integration of geonus illustration JGL at Geonu 2013 25 23 March 2013 Crust and Mantle versus Range JGL at Geonu 2013 26 Where Comes the Geonus? Account for oscillations and energy smearing One lesson of the study: oscillations are very important tool. NUDAR 23 March 2013 JGL at Geonu 2013 27 Geonu and Reactor Spectra location off Spain ~300km to nearest reactor Geonus rule! 23 March 2013 JGL at Geonu 2013 28 Seeking a Reactor: Where Comes the Background? Sum of backgrounds Spectrum of backgrounds 23 March 2013 JGL at Geonu 2013 29 23 March 2013 JGL at Geonu 2013 30 23 March 2013 Finding a Reactor and Power Output JGL at Geonu 2013 31 13 April 2009 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) John Learned at Cornell 32 23 March 2013 Increased angular resolution buys a lot JGL at Geonu 2013 33 Hanohano a mobile deep ocean detector Measure electron antinus for: Results from DARPA funded study, employing Makai Ocean Engineering for preliminary design and feasibility study. Geophysics Particle physics (hierarchy, mixing parameters) 10 kiloton liquid scintillation Remote reactor monitoring for antiproliferation. Up to ~100 kt possible And lots more science… Deploy and retrieve from barge 13 April 2009 John Learned at Cornell 34 Hanohano Engineering Studies Makai 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 13 April 2009 Barge 112 m long x 23.3 wide Deployment Sketch Descent/ascent 39 min John Learned at Cornell 35 Addressing Technology Issues Scintillating oil studies in lab 20m x 35m fiducial vol. P=450 atm, T=0°C Testing PC, PXE, LAB and dodecane No problems so far, LAB favorite… optimization needed 1 m oil Implosion studies Design with energy absorption 2m pure water Computer modeling & at sea No stoppers Power and comm, no problems Optical detector, prototypes OK Need second round design 13 April 2009 Implosion signals from empty sphere and a sphere with 30% volume filled with foam 1 0.8 Pressure (norm) 0.6 0.4 0.2 0 0.0025 -0.2 0.0035 0.0045 0.0055 0.0065 0.0075 0.0085 0.0095 -0.4 -0.6 30% Foam filled (4105m) Empty (4280m) -0.8 -1 Time (seconds) John Learned at Cornell 36 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. 13 April 2009 John Learned at Cornell 37 Summary of Expected Results Hanohano- 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…. 13 April 2009 John Learned at Cornell 38 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. 13 April 2009 John Learned at Cornell 39 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! 23 March 2013 JGL at Geonu 2013 40 JGL at Geonu 2013 23 March 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 41