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The Daya Bay Experiment Steve Kettell BNL 1)Motivation 2)Reactor anti- e 3)Daya Bay Experiment 4)Collaboration/BNL involvement.

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Presentation on theme: "The Daya Bay Experiment Steve Kettell BNL 1)Motivation 2)Reactor anti- e 3)Daya Bay Experiment 4)Collaboration/BNL involvement."— Presentation transcript:

1 The Daya Bay Experiment Steve Kettell BNL 1)Motivation 2)Reactor anti- e 3)Daya Bay Experiment 4)Collaboration/BNL involvement

2 April 18, 2006Steve Kettell, BNL DOE HEP Review2 Connecting Quarks to the Cosmos: One of the eleven `profound questions ’ addresses the mass and mixing of neutrinos. (2003) Quantum Universe: “ Detailed studies of the properties of neutrinos  their masses, how they mix, and whether they are Majorana particles  will tell us whether neutrinos conform to the patterns of ordinary matter or whether they are leading us to the discovery of new phenomena. ” (2004) recommendation of the APS Study Group (11/04) NuSAG (2/28/06) Neutrinos The U.S. should mount one multi-detector reactor experiment sensitive to  e disappearance down to sin 2 2θ 13 ~ 0.01.

3 April 18, 2006Steve Kettell, BNL DOE HEP Review3 BNL PAC BNL High Energy Nuclear Physics Program Advisory Committee meeting 3/23/06 The BNL neutrino group's presentation of the Daya Bay experiment and their involvement in it was very well received. In particular, the committee noted the crucial role BNL plays in R&D work for the Daya Bay experiment. In conjunction with the BNL Chemistry department, the group studies solubility of Gd in scintillator, and attenuation of light in the Gd doped scintillator. These R&D issues are at the heart of the potential success of both the Daya Bay and Braidwood reactor efforts. The committee recognizes and encourages the great synergy between the BNL physicists and chemists in the reactor program. PAC Membership: Stanley Brodsky, Donald Geesaman, Miklos Gyulassy, Barbara Jacak, Peter Jacobs, Bob Jaffe, Takaaki Kajita, James Nagle, Jack Sandweiss, Yannis Semertzidis, (Bonnie Fleming, Frank Sculli)

4 April 18, 2006Steve Kettell, BNL DOE HEP Review4 The Last Unknown Neutrino Mixing Angle:  13 U MNSP Matrix Maki, Nakagawa, Sakata, Pontecorvo What is  e fraction of 3 ? Is there  symmetry in neutrino mixing? U e3 is the gateway to CP violation in neutrinos. ? ? atmospheric, K2K reactor and accelerator 0  SNO, solar SK, KamLAND  12 ~ 32°  23 = ~ 45°  13 = ?

5 April 18, 2006Steve Kettell, BNL DOE HEP Review5 Distance (km) P ee PeePee Measuring  13 with Reactor Neutrinos Search for  13 in oscillation experiment U e3 ~1.8 km ~ 0.3-0.5 km Pure measurement of  13. nuclear reactor detector 1 detector 2  13 Daya Bay, China

6 April 18, 2006Steve Kettell, BNL DOE HEP Review6 Time- and energy-tagged signal is a good tool to suppress background events. Energy of  e is given by: E   T e + + T n + (m n - m p ) + m e +  T e + + 1.8 MeV 10-40 keV The reaction is inverse  -decay in 0.1% Gd-doped liquid scintillator: Arbitrary Flux Cross Section Observable Spectrum From Bemporad, Gratta and Vogel Detection of antineutrinos in liquid scintillator  e  p  e + + n (prompt)  + p  D +  (2.2 MeV) (delayed)  + Gd  Gd*  Gd +  ’s (8 MeV) (delayed) 50,000b 0.3b

7 April 18, 2006Steve Kettell, BNL DOE HEP Review7 Current Knowledge of  13 2.7% without near detectors      m  limited statistics reactor-related systematic errors: - energy spectrum of  e (~2%) - time variation of fuel composition (~1%) detector-related systematic error (1-2%) background-related error (1-2%) Established technique (e.g. Chooz)  with improvements for Daya Bay Limit on   from Chooz At  m 2 31 = 2.4  10  3 eV 2, sin 2 2   < 0.15 allowed region

8 April 18, 2006Steve Kettell, BNL DOE HEP Review8 Requirements for improving the sensitivity to sin 2 2  13  0.01 Higher statistics: More powerful reactor cores Larger target mass Better control of systematic errors: Utilize multiple detectors at different baselines (near and far)  measure RATIOS Make detectors as nearly IDENTICAL as possible Careful and thorough calibration and monitoring of each detector Optimize baseline for best sensitivity and small residual reactor- related errors Interchange detectors to cancel most detector systematics

9 April 18, 2006Steve Kettell, BNL DOE HEP Review9 Goals And Approach Utilize the Daya Bay nuclear power facilities to: - determine sin 2 2  13 with a sensitivity of 1% - measure  m 2 31 Employ horizontal-access-tunnel scheme: - mature and relatively inexpensive technology - flexible in choosing overburden and baseline - relatively easy and cheap to add experimental halls - easy access to underground experimental facilities - easy to move detectors between different locations with good environmental control. Adopt three-zone antineutrino detector design.

10 April 18, 2006Steve Kettell, BNL DOE HEP Review10 Daya Bay, China 55 km 45 km

11 April 18, 2006Steve Kettell, BNL DOE HEP Review11 Ling Ao II NPP: 2  2.9 GW th Ready by 2010-2011 Ling Ao NPP: 2  2.9 GW th The Daya Bay Nuclear Power Facilities Daya Bay NPP: 2  2.9 GW th 1 GW th generates 2 × 10 20  e per sec Powerful facilities (total thermal power): 11.6 GW (now)  17.4 GW (2011) comparable to Palo Verde, the most powerful nuclear power plant in U.S. Adjacent to mountain, easy to construct tunnels to underground labs with sufficient overburden to suppress cosmic rays

12 April 18, 2006Steve Kettell, BNL DOE HEP Review12 Daya Bay NPP Ling Ao NPP Ling Ao-ll NPP (under const.) Entrance portal Empty detectors: moved to underground halls through access tunnel. Filled detectors: swapped between underground halls via horizontal tunnels. Total length: ~2700 m 230 m (15% slope) 290 m (8% slope) 730 m 570 m 910 m Daya Bay Near 360 m from Daya Bay Overburden: 97 m Ling Ao Near 500 m from Ling Ao Overburden: 98 m Far site 1600 m from Ling Ao 2000 m from Daya Overburden: 350 m Mid site ~1000 m from Daya Overburden: 208 m

13 April 18, 2006Steve Kettell, BNL DOE HEP Review13 buffer 20 tonnes Gd-LS gamma catcher Antineutrino Detector Antineutrinos are detected via inverse  -decay in Gd-doped liquid scintillator (LS) Description: 3 zones: Gd-LS target (20 tonnes), LS gamma catcher, oil buffer 2 nested acrylic vessels, 1 stainless vessel 200 8” PMT’s on circumference of 5m  5m cylinder reflective surfaces on endplates of cylinder energy resolution is  14%/  E

14 April 18, 2006Steve Kettell, BNL DOE HEP Review14 Conceptual Design of Muon Veto Detector modules enclosed by 2m of water to shield neutrons (and gamma-rays) Water shield also serves as a Cherenkov veto Augmented with a muon tracker: scintillator or RPC's Combined efficiency of Cherenkov and tracker > 99.5% 2m of water ~0.05 Neutron background vs. thickness of water water muon tracker rock a conceptual design

15 April 18, 2006Steve Kettell, BNL DOE HEP Review15 Findings of Geotechnical Survey No active or large faults Earthquakes are infrequent Rock: massive and blocky granite Rock mass: slightly weathered or fresh Groundwater: low flow at tunnel depth Quality of rock: stable and hard Good geotechnical conditions for tunnel construction Pat Dobson (LBL) Chris Laughton (FNAL) Joe Wang (LBL) Yanjun Sheng (IGG) U.S. experts in geology and tunnel construction assist geotechnical survey: Borehole drilling

16 April 18, 2006Steve Kettell, BNL DOE HEP Review16 Tunnel construction The total tunnel length is ~3 km Preliminary civil construction design: ~$3K/m Construction time is ~24 months (  5 m/day) A similar tunnel already exists on site 7.2 m

17 April 18, 2006 Steve Kettell, BNL DOE HEP Review 17 Background Near SiteFar Site Radioactivity (Hz)<50 Accidental B/S<0.05% Fast neutron B/S 0.14%  0.16%0.08%  0.1% 8 He/ 9 Li B/S 0.41%±0.18% 0.02%±0.08% Accidental Background: Natural Radioactivity: PMT glass, Rock, Radon in the air, etc Neutrons Correlated Background: Fast neutrons Neutrons produced in rock and water shield (99.5% veto efficiency) Cosmic Ray production of 8He/9Li which can decay via  -n emission For reference, 560(80) neutrino events per detector per day at the near(far) site

18 April 18, 2006 Steve Kettell, BNL DOE HEP Review 18 Systematic Uncertainty Systematic errorChoozDaya Bay Reaction Cross Section1.9% 0, near-far cancellation Energy released per fission0.6% 0, near-far cancellation Reactor Power0.7%0.1%, near-far cancellation Number of Protons0.8%0, detector swapping Detection efficiency1.5%~0.2%, fewer cuts, detector swapping Total2.75%~0.2% Statistical Error (3 years): 0.2%2.8% (Chooz) Residual systematic error: ~ 0.2%2.7%

19 April 18, 2006Steve Kettell, BNL DOE HEP Review19 Sensitivity Daya Bay near (40t) Tunnel entrance Ling Ao near (40t) Far (80t) Antineutrino detector modules, each with 20 tonne target mass Horizontal tunnel 3-year run with 80 t at far site

20 April 18, 2006Steve Kettell, BNL DOE HEP Review20 The Daya Bay Collaboration: China-Russia-U.S. X. Guo, N. Wang, R. Wang Beijing Normal University, Beijing L. Hou, B. Xing, Z. Zhou China Institute of Atomic Energy, Beijing M.C. Chu, W.K. Ngai Chinese University of Hong Kong, Hong Kong J. Cao, H. Chen, J. Fu, J. Li, X. Li, Y. Lu, Y. Ma, X. Meng, R. Wang, Y. Wang, Z. Wang, Z. Xing, C. Yang, Z. Yao, J. Zhang, Z. Zhang, H. Zhuang, M. Guan, J. Liu, H. Lu, Y. Sun, Z. Wang, L. Wen, L. Zhan, W. Zhong Institute of High Energy Physics, Beijing X. Li, Y. Xu, S. Jiang Nankai University, Tianjin Y. Chen, H. Niu, L. Niu Shenzhen University, Shenzhen S. Chen, G. Gong, B. Shao, M. Zhong, H. Gong, L. Liang, T. Xue Tsinghua University, Beijing K.S. Cheng, J.K.C. Leung, C.S.J. Pun, T. Kwok, R.H.M. Tsang, H.H.C. Wong University of Hong Kong, Hong Kong Z. Li, C. Zhou Zhongshan University, Guangzhou Yu. Gornushkin, R. Leitner, I. Nemchenok, A. Olchevski Joint Institute of Nuclear Research, Dubna, Russia V.N. Vyrodov Kurchatov Institute, Moscow, Russia B.Y. Hsiung National Taiwan University, Taipei M. Bishai, M. Diwan, D. Jaffe, J. Frank, R.L. Hahn, S. Kettell, L. Littenberg, K. Li, B. Viren, M. Yeh Brookhaven National Laboratory, Upton, NY 11973-5000, U.S. R.D. McKeown, C. Mauger, C. Jillings California Institute of Technology, Pasadena, CA 91125, U.S. K. Whisnant, B.L. Young Iowa State University, Ames, Iowa 50011, U.S. W.R. Edwards, K. Heeger, K.B. Luk University of California and Lawrence Berkeley National Laboratory, Berkeley, CA 94720, U.S. V. Ghazikhanian, H.Z. Huang, S. Trentalange, C. Whitten Jr. University of California, Los Angeles, CA 90095, U.S. M. Ispiryan, K. Lau, B.W. Mayes, L. Pinsky, G. Xu, L. Lebanowski University of Houston, Houston, Texas 77204, U.S. J.C. Peng University of Illinois, Urbana-Champaign, Illinois 61801, U.S. 20 institutions, 89 collaborators

21 April 18, 2006Steve Kettell, BNL DOE HEP Review21

22 April 18, 2006Steve Kettell, BNL DOE HEP Review22 Accomplishments at Feb Collaboration Meeting Bylaws were ratified by the collaboration. Institutional board, with one representative from each member institution and two spokespersons, was established. Executive board was established: Y. Wang (China)A. Olshevski (Russia) C. Yang (China)K.B. Luk (U.S.) M.C. Chu (Hong Kong)R. McKeown (U.S.) Y. Hsiung (Taiwan) Scientific spokespersons were chosen: Y. Wang (China), K.B. Luk (U.S.) Project management in China and U.S. were compared. Initial discussions of construction project management. Task forces were set up. Each task is led by at least one member from China and one from U.S.

23 April 18, 2006Steve Kettell, BNL DOE HEP Review23 Collaboration Communications Weekly collaboration phone meetings Weekly U.S. Daya Bay phone meetings LBL serves as the hub for both phone meetings BNL provides web archive for phone meetings Several face-to-face collaboration meetings have been held in Beijing, Shenzhen, Hong Kong, and Berkeley. The most recent one was held at IHEP in February 2006. Next collaboration meeting in Beijing, June 9-12, 2006.

24 April 18, 2006Steve Kettell, BNL DOE HEP Review24 Joint U.S.-China Task Forces 1. Antineutrino Detector Co-Chairs: S. Kettell (BNL, U.S.) Y. Wang (IHEP, China) 2. Calibration Co-Chairs: R.D. McKeown (Caltech, U.S.) X. Biao (CIAE, China) 3. Communications Co-Chairs: J. Cao (IHEP, China) K.M. Heeger (LBNL, U.S.) W. Ngai (CUHK, Hong Kong) 4. Liquid Scintillator Co-Chairs: R.L. Hahn (BNL, U.S.) Z. Zhang (IHEP, China) I. Nemchenok (Dubna, Russia) 5. Muon Veto Co-Chairs: L. Littenberg (BNL, U.S.) K. Lau (Houston, U.S.) Y. Changgen (IHEP, China) 6. Offline Data Distribution and Processing Co-Chairs: J. Cao (IHEP) B. Viren (BNL) 7. Project Management and Integration Co-Chairs: B. Edwards (LBNL, U.S.) S. Kettell (BNL, U.S.) Y. Wang (IHEP, China) H. Zhuang (IHEP, China) 8. Simulation Co-Chairs: J. Cao (IHEP, China) C. Jillings (Caltech, U.S.) 9. Tunneling and Civil Construction Lead: C. Yang (IHEP, China) U.S. Consultant: C. Laughton (FNAL, U.S.) International working groups with U.S.-China co-leadership for main detector systems and R&D issues established at the February collaboration meeting.

25 April 18, 2006Steve Kettell, BNL DOE HEP Review25 Why BNL? The Physics is compelling! and a critical step to CP BNL provides a strong National Laboratory presence to assure the success of the experiment. BNL has a rich and storied tradition in physics: in both the Physics and Chemistry departments BNL Chemistry has been involved in liquid scintillator research for Daya Bay for 3 years This experiment provides a bridge from the current Physics Department effort on MINOS to a long-baseline effort to measure CP violation in the neutrino sector.

26 April 18, 2006Steve Kettell, BNL DOE HEP Review26 BNL involvement in Daya Bay Formally joined collaboration at Feb. 2006 meeting in Beijing Member of Institutional Board (Kettell) Lead of liquid scintillator task force (Hahn,Yeh) Lead of muon veto task force (Littenberg, Diwan, Bishai) Central detector task force (Kettell) Simulations task force (Jaffe) Project and other engineering resources available

27 April 18, 2006Steve Kettell, BNL DOE HEP Review27 BNL is deeply involved in the muon tracker design BNL is working with engineer from LBNL on antineutrino detector design and project management BNL is looking to incorporate additional BNL engineering One third of R&D request for BNL projects As MINOS analysis effort matures, more effort directed to Daya Bay construction project and later to DB analysis VLBN MINOS E734 BNL in Daya Bay

28 April 18, 2006Steve Kettell, BNL DOE HEP Review28 U.S. R&D Plan Primary R&D Goals: Ensure a strong U.S. contribution to the Daya Bay experiment. Match the schedule of Chinese R&D and design.  Don ’ t let U.S. slow project down! Optimize U.S. scope while minimizing cost. Full R&D funding in FY06 (and FY07): Enable U.S. input to experiment design. Timely technology choices. Early determination of project cost and schedule. Finalize preparations for CD-1 in about six months. DOE-HEP Daya Bay FY06 R&D Request 1/23/06, revised 1/31/06 R&D TasksFY06 ($k) 1) Simulations195 2) Liquid Scintillator255 3) Antineutrino Detector500 4) Calibration370 5) Electronics150 6) Muon Veto419 7) Site Development200 8) Project Definition265 Total2354

29 April 18, 2006Steve Kettell, BNL DOE HEP Review29 Gd-Loaded Liquid Scintillator BNL lead role: substantial R&D at BNL on metal loaded LS (funded by ONP + LDRD) Avoid the chemical/optical degradation problems encountered in the Chooz and Palo Verde experiments Primary R&D Goals: Study alternatives to PC (Low flashpoint: 48 o C, health/environmental issues, attack acrylic) – For example, mixture of 20% PC and 80% dodecane – Current R&D is with Linear Alkyl Benzene, LAB, which is very attractive (high flashpoint:130 o, biodegradable and environmentally friendly, readily available with tons produced by industry for detergents) Successfully prepared Gd-LS in 100% LAB, with favorable properties (over Gd in PC) Further studies needed to determine stability over time Develop mass-production techniques to go from the current bench-top scale of kg (several liters) to tonnes (thousands of liters) 1.Require stable (~years) Gd-LS with high light yield, long attenuation length. 2.Explore alternatives to pseudocumene, PC. 3.Evaluate chemical compatibility of Gd-LS with acrylic (detector vessel).

30 April 18, 2006Steve Kettell, BNL DOE HEP Review30 Calendar Date Absorbance at 430 nm Optical Attenuation of BNL Gd-LS Gd-LS under UV light (in 10 cm cells) Stable for ~500 days so far

31 April 18, 2006Steve Kettell, BNL DOE HEP Review31 Muon Veto/Tracker Understanding muon and spallation backgrounds: 1. High efficiency, redundant muon vetoes. 2. Tracking ability for systematic studies and event identification. Primary R&D Goals: Evaluate candidate technologies for muon tracker: Plastic scintillator strips Resistive Plate Chambers Liquid scintillator modules Evaluate candidate technologies for muon veto: Water pool Cherenkov Modular water Cherenkov BNL Role Subsystem in which U.S. is likely to take the lead  BNL has extensive experience in both plastic and liquid scintillator.

32 April 18, 2006Steve Kettell, BNL DOE HEP Review32 Primary R&D Goals: Mechanical design of central detector. Design of transportation and installation systems for detectors. Identify vendors for fabricating acrylic vessels. BNL Role: Engineering and leadership experience at LBNL and BNL. On the critical path (civil construction design contract). Antineutrino Detector Measurement of sin 2 2  13  0.01 requires detector systems designed to minimize systematic uncertainties. 1.Identical detector modules: identical scintillator volumes, optical transparency. facilitate calibration/monitoring system. 2.Moveable detectors: design detectors for identical performance at all sites. engineer support and movement structures. time critical due to close interface with tunnel/cavern design. KamLAND 2005

33 April 18, 2006Steve Kettell, BNL DOE HEP Review33 Site Development 1.Analyze core samples: input for detailed civil construction design studies. 2.Define surface building and underground halls (space and infrastructure). 3.Define liquid scintillator purification and handling (space and infrastructure). Primary R&D Goals: Define underground hall specifications in order to proceed to final civil design contract. Interface between experiment design and hall design. BNL Role: Engineering and physics design experience Specification of civil design is on the critical path; minimize delay and reduce risk for civil construction. KamLAND 2005

34 April 18, 2006Steve Kettell, BNL DOE HEP Review34 Project Definition 1.Develop complete project scope and schedule (joint with China). 2.Define U.S. and Chinese deliverables (joint with China). 3.Develop U.S. cost and schedule ranges. 4.Build U.S. project team and organization. Primary R&D Goals: Develop the U.S. project scope, cost and schedule. Coordinate with China on total project scope, cost and schedule. BNL Role: U.S. responsibility. Exploit project experience at LBNL and BNL. Continue to develop coordination with Chinese effort. Develop baseline project. Develop overall experiment design. KamLAND 2005

35 April 18, 2006Steve Kettell, BNL DOE HEP Review35 Initial definition of Project Scope Muon tracking system (veto system) Gd-loaded liquid scintillator Calibration systems Antinu Detector (Acrylic, PMT ’ s) Electronics/DAQ/trigger hardware Detector integration activities Project management activities U.S.-China primary responsibilities U.S. Scope Russia: liquid scintillator, calibration, and plastic scintillator Taiwan: acrylic vessels and trigger Hong Kong: calibration and data storage other contributions

36 April 18, 2006Steve Kettell, BNL DOE HEP Review36 U.S. Project Scope & Budget

37 April 18, 2006Steve Kettell, BNL DOE HEP Review37 Overall Project Schedule

38 April 18, 2006Steve Kettell, BNL DOE HEP Review38 Project Development Schedule/activities over next several months: Determine scale of detector for sizing halls: Continue building strong U.S. team - key people: Conceptual design, scale & technology choices: Firm up U.S. scope, schedule & cost range: Write CDR, prepare for CD-1: now – June now – summer now – Aug July – Nov Aug – Nov

39 April 18, 2006Steve Kettell, BNL DOE HEP Review39 Funding Profile CD-1 reviewNovember 2006 Begin construction in ChinaMarch 2007 CD-2 reviewSeptember 2007 Begin data collection January 2010 Measure sin 2 2  13 to 0.01March 2013 FY06U.S. R&D $2M FY07 $3.5M FY08U.S. Construction $10M FY09 $14M FY10 $8M

40 April 18, 2006Steve Kettell, BNL DOE HEP Review40 Summary and Prospects The Daya Bay nuclear power facility in China and the mountainous topology in the vicinity offer an excellent opportunity for carrying out a measurement of sin 2 2  13 at a sensitivity of 0.01. The Chinese funding agencies have agreed in principle to a request of RMB 150M to fund civil construction and ~half of the detector. NuSAG endorsed U.S. participation in a  13 experiment, P5 is evaluating  13 experiments as part of the Roadmap, and we are hopeful for a positive decision by DOE. BNL/LBNL submitted R&D request to DOE for FY06 in January 2006. Have begun to form project leadership team with China: progress on organization, scope and cost. Will complete a conceptual design of detectors, tunnels and underground facilities in 2006, aiming for CD1 review this year and a CD2 review in 2007. In the ~3 months since BNL joined the Daya Bay collaboration we have made huge strides in defining and understanding the project and the U.S. scope. Plan to commission a Fast Deployment plan in 2009, with full operation in 2010.

41 April 18, 2006Steve Kettell, BNL DOE HEP Review41 Backup

42 April 18, 2006Steve Kettell, BNL DOE HEP Review42 A Versatile Site Rapid deployment: - Daya Bay near site + mid site - 0.7% reactor systematic error Full operation: (A) Two near sites + Far site (B) Mid site + Far site (C) Two near sites + Mid site + Far site Internal checks, each with different systematic

43 April 18, 2006Steve Kettell, BNL DOE HEP Review43 ~350 m ~97 m ~98 m ~208 m Cosmic-ray Muon Apply a modified Gaisser parameterization for cosmic-ray flux at surface Use MUSIC and mountain profile to estimate muon flux & energy DYBLingAoMidFar Elevation (m)9798208347 (m.w.e.)280 560930 Flux (Hz/m 2 )1.20.940.170.045 Mean Energy (GeV)55 97136 near site far site

44 April 18, 2006Steve Kettell, BNL DOE HEP Review44 Science Goals → Experiment Design → R&D Reduce and control systematic errors: “Identical” detectors at multiple sites → detector design/construction, side-by-side comparisons U.S. R&D tasks focused on achieving these goals Detector performance - well-understood, stable → materials/construction, calibration/monitoring Reduce radioactivity background → materials/construction, Gd-loaded scintillator Reduce and measure cosmogenic backgrounds → shielding, muon veto and tracking, DAQ system Swap detectors → horizontal tunnel system, locomotion equipment

45 April 18, 2006Steve Kettell, BNL DOE HEP Review45 Background estimated by GEANT MC simulation Nearfar Neutrino signal rate(1/day)56080 Natural backgrounds(Hz)45.3 Single neutron(1/day)242 Accidental BKG/signal0.04%0.02% Correlated fast neutron Bkg/signal0.14%0.08% 8 He+ 9 Li BKG/signal0.5%0.2%

46 April 18, 2006Steve Kettell, BNL DOE HEP Review46 Detector-related Uncertainties Baseline: currently achievable relative uncertainty without R&D Goal: expected relative uncertainty after R&D Absolute measurement Relative measurement → 0 → 0.006 → 0.06% w/Swapping → 0 Swapping: can reduce relative uncertainty further

47 April 18, 2006Steve Kettell, BNL DOE HEP Review47 Experimental Parameters

48 April 18, 2006Steve Kettell, BNL DOE HEP Review48 H/C ratio CHOOZ claims 0.8% absolute based on multiple lab analyses (combustion) We need only relative measurement Double-CHOOZ claims 0.2%  Adopt 0.2% baseline  Adopt 0.1% goal R&D: measure via NMR or neutron capture

49 April 18, 2006Steve Kettell, BNL DOE HEP Review49 Target Volume KamLAND: ~1% CHOOZ: 0.02%? Flowmeters – 0.02% repeatability  Baseline = 0.2%  Goal = 0.02%

50 April 18, 2006Steve Kettell, BNL DOE HEP Review50 Energy Cuts CHOOZ = 0.8% absolute Baseline 0.2% Goal = 0.05% for 2% energy calibration

51 April 18, 2006Steve Kettell, BNL DOE HEP Review51 Energy Cuts KamLAND calibration data:

52 April 18, 2006Steve Kettell, BNL DOE HEP Review52 Time Cuts Neutron time window uncertainty:   t = 10 ns  0.03% uncertainty  Use common clock for detector modules  Baseline = 0.1%  Goal = 0.03%

53 April 18, 2006Steve Kettell, BNL DOE HEP Review53 H/Gd ratio CHOOZ measured  to ±0.5  s   =0.01% for t 1 =0.2  s Measure neutron capture time

54 April 18, 2006Steve Kettell, BNL DOE HEP Review54 Livetime Measure relative livetimes using accurate common clock Should be negligible error (note SNO livetime error of ~10 -5

55 April 18, 2006Steve Kettell, BNL DOE HEP Review55 What Have We Learned From Chooz? CHOOZ Systematic Uncertainties Reactor  flux & spectrum Detector Acceptance 2% 1.5% Total 2.7% 5 t Gd-loaded liquid scintillator to detect L = 1.05 km D = 300 mwe P = 8.4 GW th Rate: ~5 events/day/t (full power) including 0.2-0.4 bkg/day/t  e + p  e + + n e + + e -  2 x 0.511 MeV  n + Gd  8 MeV of  s;  ~ 30  s ~3000  e candidates (included 10% bkg) in 335 days

56 April 18, 2006Steve Kettell, BNL DOE HEP Review56 Reactor anti- e For 235 U, for instance, a n average of 6 e s are produced per fission (~200 MeV).  e /MeV/fission 3 GW th generates 6  10 20  e per sec -42

57 April 18, 2006Steve Kettell, BNL DOE HEP Review57 Time Variation of Fuel Composition Typically known to ~1% 235 U 238 U 239 Pu 241 Pu normalized flux times cross section (arbitrary units) 0 0.5 1 1.5 2 2.5 3 3.5 12 3 4 5 6 7 8 9 10 E (MeV)

58 April 18, 2006Steve Kettell, BNL DOE HEP Review58 Calibration Radioactive Source 137 Cs, 22 Na, 60 Co, 54 Mn, 65 Zn, 68 Ge, Am-Be 252 Cf, Am-Be Gamma generator p+ 19 F→ α+ 16 O*+6.13MeV; p+ 11 B→ α+ 8 Be*+11.67MeV Backgrounds 40 K, 208 Tl, cosmic-induced neutrons, Michel ’ s electrons, … LED calibration KI & CIAE Hong Kong

59 April 18, 2006Steve Kettell, BNL DOE HEP Review59 What Target Mass Should Be? Systematic error Black : 0.6% DYB: B/S = 0.5% LA: B/S = 0.4% Far: B/S = 0.1%  m 2 31 = 2  10 -3 eV 2 tonnes (3 year run) Red : 0.25% (baseline goal) Blue : 0.12%

60 April 18, 2006Steve Kettell, BNL DOE HEP Review60 Sensitivity For 3 years With four 20-t modules at the far site and two 20-t modules at each near site:

61 April 18, 2006Steve Kettell, BNL DOE HEP Review61 Precision of  m 2 31 sin 2 2  13 = 0.02 sin 2 2  13 = 0.1

62 April 18, 2006Steve Kettell, BNL DOE HEP Review62 Synergy of Reactor and Accelerator Experiments Δ m 2 = 2.5×10 -3 eV 2 sin 2 2  13 = 0.05 Reactor experiments can help in Resolving the  23 degeneracy (Example: sin 2 2  23 = 0.95 ± 0.01) 90% CL Reactor w 100t (3 yrs) + Nova Nova only (3yr + 3yr) Reactor w 10t (3yrs) + Nova 90% CL McConnel & Shaevitz, hep-ex/0409028 90% CL Reactor w 100t (3 yrs) +T2K T2K (5yr, -only) Reactor w 10t (3 yrs) +T2K Reactor experiments provide a better determination of  13


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