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Future Reactor and Solar Neutrino Facilities

Future Reactor and Solar Neutrino Facilities. near. S. Biller, Oxford University.  Reactor Experiments. (  13 ). ν e. ν e. ν e. ν e. ν e. ν e. sin 2 2 θ 13. 2. 2. 2. P. (. ). 1. sin. 2. sin. (. 1. 27. m. L. /. E. ). n. . n. =. -. q. D. e. e.

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Future Reactor and Solar Neutrino Facilities

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  1. Future Reactor and Solar Neutrino Facilities near S. Biller, Oxford University

  2. Reactor Experiments (13)

  3. νe νe νe νe νe νe sin22θ13 2 2 2 P ( ) 1 sin 2 sin ( 1 . 27 m L / E ) n  n = - q D e e 13 13 n Reactor Neutrinos Well understood, isotropic source of electron anti-neutrinos Oscillations observed as disappearance of νe Eν≤ 8 MeV 1.0 Probability νe Survival Probability + O(Dm122 / Dm132) Distance No q23 ambiquity; No d-CP effects; No matter effects; Minimal dependence on Dm122

  4. Another Reason for Multiple Approaches: These measurements are difficult! So, it’s important to have independent measurements with comparable sensitivities using approaches with different systematics

  5. Krasnoyarsk Double Chooz Braidwood Daya Bay KASKA Diablo Canyon Reno Angra

  6. Krasnoyarsk Double Chooz Braidwood Daya Bay KASKA Diablo Canyon Reno Angra

  7. Comparison of Reactor Neutrino Experiments

  8. n ne+p e+ Gd* Gd-loaded scintillator

  9. Backgrounds • There are two types of background… • Uncorrelated − Two random events that occur close together in space and time and mimic the parts of the coincidence. • This BG rate can be estimated by measuring the singles rates, or by switching the order of the coincidence events. • Correlated − One event that mimics both parts of the coincidence signal. • These may be caused by fast neutrons (from cosmic m’s) that strike a proton in the scintillator. The recoiling proton mimics the e+ and the neutron captures. • Or they may be cause by muon produced isotopes like 9Li and 8He which sometimes decay to β+n. • Estimating the correlated rate is much more difficult!

  10. n ne+p e+ p n n m m Gd-loaded scintillator

  11. Gd* Gd-loaded scintillator

  12. Double Chooz detector concept (adopted by all)  target: 80% dodecane + 20% PXE + 0.1% Gd -catcher: 80% dodecane + 20% PXE 511 keV 511 keV Non-scintillating buffer oil e+ e p Gd n Buffer stainless steel tank + 400 PMTs (10’)  ~ 8 MeV Muon VETO: scintillating oil Steel Shielding 7 m 7 m • Mechanically complex construction • Asymmetric • Difficult to calibrate • Untested • Necessity unclear for 2 position measurement

  13. (Sussex) Double Chooz Far Detector:L = 1050 m300 mwe ~50 events/day Near Detector: <L> = 415 m210 mwe ~550 events/day Reactor cores Chooz Nuclear Power Plant Northern France 2 units with thermal output of 8.7 GW

  14. Near detector Far detector

  15. CHOOZ Double-Chooz Target volume 5,55 m3 10,2 m3 Target composition 6,77 1028 H/m3 6,82 1028 H/m3 Data taking period Few months 3-5 years – Systematic error – Event rate 2700 CHOOZ-far : 50 000/3 y CHOOZ-near: ~1 106/3 y Statistical error 2,7% No reconstruction cut on fiducial volume More uniform detection efficiency 0,5% Relative measurement using 2 “identical” detectors Improving CHOOZ results @CHOOZ: R = 1.01  2.8%(stat)  2.7%(syst) – Statistical error – Luminosity incerase L = t x P(GW) x Np

  16. Provides a simple, adaptable system for non-intrusive, in situ calibration with elements fixed in a well-defined, stable geometry Continuously monitor detector stability Calibrate relative PMT timing Study optical characteristics at different wavelengths

  17. SoI from Sussex recently submitted

  18. Daya Bay nuclear power plant • 4 reactor cores, 11.6 GW • 2 more cores in 2011, 5.8 GW • Mountains near by • 55 km to Hong Kong 55 km

  19. Europe (3) JINR, Dubna, Russia Kurchatov Institute, Russia Charles University, Czech Republic North America (14) BNL, Caltech, LBNL, Iowa state Univ. Illinois Inst. Tech., Princeton, RPI, UC-Berkeley, UCLA, Univ. of Houston, Univ. of Wisconsin, Virginia Tech., Univ. of Illinois-Urbana-Champaign, George Mason Univ. Asia (18) IHEP, CIAE,Tsinghua Univ. Zhongshan Univ.,Nankai Univ. Beijing Normal Univ., Nanjing Univ. Chengdu Univ. Tech., Shandong Univ. Shenzhen Univ., Hong Kong Univ. USTC,Chinese Hong Kong Univ. Taiwan Univ., Chiao Tung Univ., National United Univ.,CGNPG, Dongguan Univ. Tech. ~ 160 collaborators

  20. Experimental Layout Far site 1615 m from Ling Ao 1985 m from Daya Bay Overburden: 350 m Ling Ao Near site ~500 m from Ling Ao Overburden: 112 m Daya Bay Near site 363 m from Daya Bay Overburden: 98 m

  21. Anti-neutrino detector design • Three zones modular structure: Target: 20t, 1.6m Gd-loaded scintillator -catcher: 20t, 45cm normal scintillator Buffer shielding: 40t, 45cm oil • Reflector at top and bottom • 192 8”PMT/module • PMT coverage: 12%(with reflector) sE/E = 12%/E sr = 13 cm TAUP 2007, Sendai

  22. AD modules in far site

  23. Muon veto detector design Multiple muon veto detectors: • RPC’s at the top as muon tracker • Water pool as Cherenkov counter has inner/outer regions • Combined eff. > (99.5  0.25) %

  24. Reactor Experiment for Neutrino Oscillation

  25. RENO Collaboration • Chonnam National University • Dongshin University • Gyeongsang National University • Kyungpook National University • Pusan National University • Sejong University • Seoul National University • Sungkyunkwan University • Institute of Nuclear Research RAS (Russia) • Institute of Physical Chemistry and Electrochemistry RAS (Russia) +++ http://neutrino.snu.ac.kr/RENO

  26. Near Detector Tunnel Length 100 m 70 m Hill Tunnel Length 300 m 1.4 km 200 m Mt. Far Detector Schematic Setup of RENO at YongGwang

  27. Experimental Hall Detector Access Tunnel 200m high (4m high ☓ 4m wide) 70m high 100m 300m 290m 1,380m Near Detector Far Detector Schematic View of Underground Facility

  28. RENO Detector Veto Buffer Dimensions total ~300 tons Target g-catcher

  29. q13 limit from global analysis T. Schwetz hep-ph/0606060 sin2 2q13 < 0.11 @ 90% CL

  30. current bound (Chooz + 3 constraint) 0.10 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 sin2(213) sensitivity at 90% C.L. Double Chooz RENO Daya Bay 2008 2009 2010 2011 2012 2013 2014 2015

  31. current bound (Chooz + 3 constraint) 0.10 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 T2K sin2(213) sensitivity at 90% C.L. Double Chooz RENO Daya Bay 2008 2009 2010 2011 2012 2013 2014 2015

  32. current bound (Chooz + 3 constraint) 0.10 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 Double Chooz T2K sin2(213) sensitivity at 3 detection level RENO Daya Bay 2008 2009 2010 2011 2012 2013 2014 2015

  33. E-776 Savannah River Bugey E-816

  34. The Two Golden Rules of Neutrino Physics: 1) Redundancy 2) Redundancy

  35. Solar Experiments (near term)

  36. Present: Very Near Future: • Borexino has made 1st measurement of 7Be neutrinos Measurement of 7Be has potential to improve pp from Ga experiments and give information on LMA, sterile n, and S34 • q12 and Dm122 determined by SNO, KamLAND (KL) and S-K. Push to lower energies (LETA, SK III) and reduced errors • Limit on q13 under 3 scenario at level of ~0.1 in sin2213 • PeeSNO sin2q12cos4q13(MSW)PeeKL  (1 - 0.39sin22q12)cos4q13(Vac) • Robertson nucl-ex/0602005; Fogli et al hep-ex/0506083 Limit will improve somewhat due to more accurate constraints from SNO, Kamland and Borexino Improved constraints should appear soon

  37. Next Goals: pep & CNO neutrinos • pep n at 1.4 MeV probes MSW upturn at low energies, • tests for non-standard interactions • pp and pep n fluxes direct test of luminosity constraint • CNO n gives information on age of Globular Clusters • Generally important to measure fundamental processes

  38. KamLAND • 1000 tons (80% dodecane, 20% pseudocumene) • 1880 PMTs (17” and 20”) • 34% photocathode coverage • singles spectrum shows 210Pb and 85Kr and also 40K contamination must purify liquid scintillator to achieve solar n sensitivity goal: 105 to 106 reduction

  39. SNO SNO+ • 2092 meters deep underground • 1000 tons of ultrapure D2O • in a 12 meter diameter • acrylic vessel • 1000 tons of ultrapure liquid • scintillator in a 12 meter • diameter acrylic vessel Already Exists ! • 7000 tons of ultrapure H2O • as shield • 9500 PMTs mounted on a • 18 meter diameter frame • electronics, DAQ, • understanding of our detector

  40. (first phase) Fill with Liquid Scintillator • SNO plus liquid scintillator physics program • pep and CNO low energy solar neutrinos • tests the neutrino-matter interaction, sensitive to new physics • geo-neutrinos • 240 km baseline reactor neutrino oscillations • supernova neutrinos • double beta decay

  41. SNO+ Collaboration Queen’s University M. Boulay, M. Chen, X. Dai, E. Guillian, P. Harvey, C. Kraus, C. Lan, A. McDonald, V. Novikov, S. Quirk, P. Skensved, A. Wright University of Alberta A. Hallin, C. Krauss Carleton University K. Graham Laurentian University D. Hallman, C. Virtue SNOLAB B. Cleveland, F. Duncan, R. Ford, N. Gagnon, J. Heise, C. Jillings, I. Lawson Brookhaven National Laboratory R. Hahn, M. Yeh, Y. Williamson Idaho State University K. Keeter, J. Popp, E. Tatar University of Pennsylvania G. Beier, H. Deng, B. Heintzelman, J. Klein, J. Secrest University of Washington N. Tolich, J. Wilkerson University of Dresden K. Zuber LIP Lisbon S. Andringa, N. Barros, J. Maneira University of Sussex S. Peeters University of Oxford S. Biller, N, Jelley, J, Wilson

  42. SNO+ AV Hold Down Existing AV Support Ropes

  43. SNO+ AV Hold Down Existing AV Support Ropes AV Hold Down Ropes

  44. Background from 11C Eliminated • SNO+ is at 6000 m.w.e. depth • muon flux reduced a factor 800 compared to Kamioka and a factor 100 compared to Gran Sasso • recall KamLAND’s post-purification goal KamLAND and Borexino will try to tag and veto the 11C to suppress at SNO+ depth this background is already smaller than the signal and one can still tag and veto

  45. SNO+ pep Solar Neutrino Signal 3600 pep events/(kton·year), for electron recoils >0.8 MeV

  46. SNO+ Double Beta Decay • a liquid scintillator detector has poor energy resolution; but enormous quantities of isotope (high statistics) and low backgrounds help compensate • large, homogeneous liquid detector leads to well-defined background model • fewer types of material near fiducial volume • meters of self-shielding • possibly source in–source out capability

  47. table from F. Avignone Neutrino 2004 150Nd • 3.37 MeV endpoint • (9.7 ± 0.7 ± 1.0) × 1018 yr 2nbb half-life measured by NEMO-III • isotopic abundance 5.6% 1% natural Nd-loaded liquid scintillator in SNO+ has 560 kg of 150Nd compared to 37 g in NEMO-III • cost: $1000 per kg for metallic Nd; cheaper is NdCl3…$86 per kg for 1 tonne

  48. Nd-Loaded Scintillator • using the carboxylate technique that was developed originally for LENS and now also used for Gd-loaded scintillator • we successfully loaded Nd into pseudocumene and in linear alkylbenzene (>1% concentration) • with 1% Nd loading (natural Nd) we found very good neutrinoless double beta decay sensitivity…

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