Neutrino Geoscience a brief history

Transcription

1 Neutrino Geoscience a brief history 1930 Pauli invokes the neutrino 1956 Reines & Cowan detect νe 1984 Krauss et al develop the map 2003 KamLAND shows νe oscillate 2005 KamLAND detects first geonus 2010 Borexino 4.2σ on Earth signal 2011 νe signal require primordial heat 2013 Combine detector events to reveal the mantle signal 2020 Neutrino Tomography! (?) Physics and Geology Collabora5ons bring the best results

2 Detec5ng Geoneutrinos from the Earth 2010

3 Nature & amount of Earth s thermal power radiogenic heating vs secular cooling - abundance of heat producing elements (K, Th, U) in the Earth - clues to planet formation processes estimates of BSE from 9TW to 36TW constrains chondritic Earth models - amount of radiogenic power to drive mantle convection & plate tectonics estimates of mantle 1.3TW to 28TW - is the mantle compositionally layered? or has large structures? layers, LLSVP, superplume piles the future is Geoneutrino studies

4 U content of BSE models Nucelosynthesis: U/Si and Th/Si production probability Solar photosphere: matches C1 carbonaceous chondrites Estimate from Chondrites: ~11ppb planet (16 ppb in BSE) Heat flow: secular cooling vs radiogenic contribution? Modeling composition: which chondrite should we use? A brief (albeit biased) history of U estimates in BSE: Urey (56) 16 ppb Turcotte & Schubert (82; 03) 31 ppb Wasserburg et al (63) 33 ppb Hart & Zindler (86) 20.8 ppb Ganapathy & Anders (74) 18 ppb McDonough & Sun (95) 20 ppb ± 20% Ringwood (75) 20 ppb Allegre et al (95) 21 ppb Jagoutz et al (79) 26 ppb Palme & O Neill (03) 22 ppb ± 15% Schubert et al (80) 31 ppb Lyubetskaya & Korenaga (05) 17 ppb ± 17% Davies (80) ppb O Neill & Palme (08) 10 ppb Wanke (81) 21 ppb Javoy et al (10) 12 ppb

5 Earth Models Update: just the last year! Murakami et al (May , Nature): the lower mantle is enriched in silicon consistent with the [CI] chondritic Earth model. Campbell and O Neill (March , Nature): Evidence against a chondritic Earth Zhang et al (March , Nature Geoscience): The Ti isotopic composition of the Earth and Moon overlaps that of enstatite chondrites. Fitoussi and Bourdon (March , Science): Si isotopes support the conclusion that Earth was not built solely from enstatite chondrites. Warren (Nov , EPSL): Among known chondrite groups, EH yields a relatively close fit to the stable-isotopic composition of Earth. - Compositional models differ widely, implying a factor of three difference in the U & Th content of the Earth

6 Enstatite chondrite vs Carbonaceous chondrites Earth diagrams from Warren (2011, EPSL) Carbonaceous chondrites Carbonaceous chondrites

7 142 Nd: what does it tell us about the Earth and chondrites? Please stop saying that the ε 142 Nd = 18 ± 5 ppm for chondrites J Data from: Gannoun et al (2011, PNAS); Carlson et al (Science, 2007) Andreasen & Sharma (Science, 2006); Boyet and Carlson (2005, Science); Jacobsen & Wasserburg (EPSL, 1984); Qin et al (GCA, 2011)

8 Earth s surface heat flow 46 ± 3 (47 ± 1) TW total R* 20 ± 4 Crust R* (7 ± 1 TW) (Huang et al 13) Mantle R* (13 ± 4 TW) Mantle cooling (18 TW) Core (~9 TW) - (4-15 TW) *R radiogenic heat (after McDonough & Sun 95) (0.4 TW) Tidal dissipation Chemical differentiation after Jaupart et al 2008 Treatise of Geophysics

9 Summary of geoneutrino results MODELS Cosmochemical: uses meteorites O Neill & Palme ( 08); Javoy et al ( 10); Warren ( 11) Geochemical: uses terrestrial rocks McD & Sun 95; Allegre et al 95; Palme O Neil 03 Geodynamical: parameterized convec5on Schubert et al; TurcoIe et al; Anderson

10 Constructing a 3-D reference model Earth assigning chemical and physical states to Earth voxels

11 3D imaging of the Earth s K-Th-U distribution Surface geoneutrino flux Yu Huang et al (2013) arxiv:

12 Early Earth differen5a5on followed by 4 billion years of plate tectonics Kellog et al (sciences 2000)

13 What s hidden in the mantle? Seismically slow red regions in the deep mantle Can we image it with geonus? No, not that CMB, Core Mantle Boundary Retsima et al (Science, 1990)

14 Forming the Moon from terrestrial silicate- rich material (2013) R.J. de Meijer, V.F. Anisichkin, W. van Westrenen (Chemical Geology). Forming the Moon from a geo- reactor at the core- mantle boundary 4.5 Ga The latest form of fission hypothesis for the origin of the Moon

15 Mantle geonuetrino flux Mantle = BSE - Crust 14+8 TNU Bellini et al TW 3-8 TW Depleted MORB Mantle TNU "UNIF" mantle "EL" with A&McD DM "EL" with S&S DM "EL" with W&H DM 6-10 TW EL : hot basal layer 5 0 N/A Cosmochemical Geochemical Geodynamical Low Q (10 ppb U) Med. Q (20 ppb U) High Q (30 ppb U)

16 Predicted geoneutrino flux Flux at the surface dominated by Continental crust Yu Huang et al (2013) arxiv: Flux at the Moho dominated by deep mantle structures Šrámek et al (2013) /j.epsl ; arxiv:

17 Present and future LS-detectors SNO+, Canada (1kt) Borexino, Italy (0.6kt) KamLAND, Japan (1kt) Europe LENA, EU (50kt) Hanohano, US ocean-based (10kt)

18 Future Experiments: world- wide deployable Pauli class research submarine Living and research quarters 10 ktons Hanohano- like Next Gen or WIMP detector ν Liquid scin5lla5on Liquid Ar, Xe Segmented research vessel with two detectors Coincidence coun5ng detectors

19 The RV ν-star International Collaboration Geosciences - Neutrino tomography Physics - Fundamental matter studies Applied - Reactor studies ν L io t a l l i int AN OVERVIEW Liqu i e X, r da n sc d i iqu LOCATIONS - anywhere in the ocean - depth of 1k - 4k m.w.e. to reduce m-&cosmogenic bkgd - ν-beam studies GOALS mass hierachy CP violation reactor neutrinos mantle geoneutrinos artificial neutrino sources supernova neutrinos + geology, biology, monitoring

20 SUMMARY (~before today ) Earth s radiogenic (Th & U) power 22 ± 12 TW or 11.2 Predic5on: models range from 8 to 28 TW (for Th & U) TW On- line and next genera5on experiments: - SNO+ online 2013/14 J - Daya Bay II: good experiment, limited geonu applica5on? - LENA??: will the Europeans push on, put LENA in the ocean! - Hanohano or RV ν- Star: this is FUNDAMENTAL for geosciences Geology must par`cipate and it must contribute to the cost - - experiment cost ~$300M; Geology s contribu5on $150M; Interna5onal - - Future: - Neutrino Tomography of the Earth s deep interior J