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The Daya Bay Reactor Antineutrino Experiment. Steve Kettell BNL. Why Daya Bay? Status/BNL involvement. The Last Mixing Angle: 13. ?. ?. U MNSP Matrix Maki, Nakagawa, Sakata, Pontecorvo. reactor and accelerator MINOS, Double Chooz Daya Bay. atmospheric, K2K, MINOS.
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The Daya Bay Reactor Antineutrino Experiment Steve Kettell BNL • Why Daya Bay? • Status/BNL involvement Physics Symposium: Steve Kettell
The Last Mixing Angle: 13 ? ? UMNSP Matrix Maki, Nakagawa, Sakata, Pontecorvo reactor and accelerator MINOS, Double Chooz Daya Bay atmospheric, K2K, MINOS SNO, solar SK, KamLAND 0 13<12° 23~45° 12~32° • Motivations to measure 13 • Key to leptonic CP violation. • How to extend the SM? • What ise fraction of 3? • Is there symmetry in mixing? Physics Symposium: Steve Kettell
Measuring sin2213 with Reactor Antineutrinos 13 ne disappearance probability • No dependence on CP or matter effects • Cost effective • Rapid deployment Pee detector 1 detector 2 nuclear reactor sin22 = 0.1 Distance (km) ~1.8 km ~ 0.3-0.5 km Daya Bay, China Physics Symposium: Steve Kettell
Daya Bay Strategy for 13 Daya Bay projected uncertainty! Limit on q13 from Chooz sin22 < 0.17 (m231 = 2.5 103 eV2) Physics Symposium: Steve Kettell
Antineutrino Detector liquid scintillator mineral oil Gd-LS Water shield Far Ling Ao near Ling Ao II cores (under construction) Water hall Construction tunnel Ling Ao cores LS hall Entrance Daya Bay near 4x20 ton (far) Daya Bay cores Physics Symposium: Steve Kettell
Daya Bay @ BNL • The Physics is compelling! and a critical step to CP • Measuring Beyond the Standard Model parameters now! • Diversity for Physics Department: complementary to LHC • BNL has a rich tradition in n physics: in both Physics and Chemistry departments (2 Nobel Prizes) • Good match to the existing Physics Department effort on MINOS and future long-baseline experiment to measure CP violation in the neutrino sector. • Priority with DOE - HEP Physics Symposium: Steve Kettell
Sensitivity Far hall (80 t) Ling Ao near hall (40 t) Daya Bay near hall (40 t) Tunnel entrance sin2213<0.01 (90% CL) over allowed Dm2 3-year run with 80 t at far site Currently allowed range of Dm2 90% C.L. • Rate and spectral shape • Relative detector systematic error of 0.2% Reactor pairs Physics Symposium: Steve Kettell
Daya Bay Status • APS multi-divisional study recommends reactor experiment (2004) • CD-0: 11/2005 • BNL formally joins collaboration 2/2006 • NuSAG endorses DB goal and DB expt. as one option 2/2006 • PAC endorses BNL involvement 3/23/2006 • Successful DOE Physics Review 10/16/2006 • P5 Roadmap: Recommends Daya Bay 10/2006 • CD-1: 9/28/2007 today • Start of Civil construction 10/2007 (groundbreaking 10/13) • CD-2/3a baseline review 1/8/2008 at BNL • CD-3b construction start Spring 2008 • CD-4b start of full operations fall 2010 Physics Symposium: Steve Kettell
Summary • The measurement of q13 at Daya Bay is a key part of the US HEP program • This measurement is important in its own right and for future experiments to search for CP violation in neutrinos • All sites ready to take data in 2010. • BNL is the largest US group on Daya Bay (2nd overall after IHEP) • Important part of the overall BNL neutrino plan (along with MINOS and Long Baseline/DUSEL) Physics Symposium: Steve Kettell
Backup Physics Symposium: Steve Kettell
Europe (3) (9) JINR, Dubna, Russia Kurchatov Institute, Russia Charles University, Czech Republic North America (14)(50) BNL, Caltech, George Mason Univ., 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, Asia (15) (86) IHEP, Beijing Normal Univ., Chengdu Univ. of Sci. and Tech., CGNPG, CIAE, Dongguan Polytech. Univ., Nanjing Univ.,Nankai Univ., Shenzhen Univ., Tsinghua Univ., USTC, Zhongshan Univ., Hong Kong Univ. Chinese Hong Kong Univ., Taiwan Univ., Chiao Tung Univ., National United Univ. ~ 145 collaborators Daya Bay collaboration Physics Symposium: Steve Kettell
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 Physics Symposium: Steve Kettell
Detection of antineutrinos in liquid scintillator e p e+ + n(prompt) 0.3b + p D + (2.2 MeV) (delayed) 50,000b • + Gd Gd* Gd + ’s(8 MeV) (delayed) From Bemporad, Gratta and Vogel Arbitrary Observable n Spectrum • Time- and energy-tagged signal is a good • tool to suppress background events. Cross Section • Energy ofe is given by: Flux 10-40 keV • inverse -decay in Gd-doped liquid scintillator: 0.1% Gd ETe+ + Tn + (mn - mp) + me+ Te+ + 1.8 MeV Physics Symposium: Steve Kettell
Sensitivity to sin2213 0.01 • High statistics: • Powerful reactor cores • Large target mass • 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 • Possible to interchange detectors to further cancel most detector systematics Physics Symposium: Steve Kettell
Antineutrino Detector Gd-LS 11.6% liquid scintillator mineral oil 12.5cm Water shield • Antineutrinos are detected via inverse -decay • in Gd-doped liquid scintillator (LS) • Description: • 3 zones: Gd-LS target (20 tons), LS gamma catcher, oil buffer • 2 nested acrylic vessels, 1 stainless vessel • 192 PMT’s on circumference of 5m5m cylinder • reflectors on endplates of cylinder • energy resolution: Physics Symposium: Steve Kettell
Muon System • Muon Veto - suppress spallation neutrons - require 99.5% efficiency • Water shield (2.5m) - rock neutrons - radioactivity • Water Cherenkov detectors with • 963 PMTs in 3 sites • 756 RPC chambers over top of • 3 pools (6048 readout strips) Physics Symposium: Steve Kettell
Daya Bay Nuclear Power Facilities Ling Ao II NPP: 2 2.9 GWth Ready by 2010-2011 Ling Ao NPP: 2 2.9 GWth • World’s 12th most powerful (11.6 GWth) • 5th most powerful by 2011 (17.4 GWth) • Adjacent to mountains, facilitates tunnels to underground labs with sufficient overburden to suppress cosmic rays (flexibility to move detectors) 1 GWth generates 2 × 1020 e per sec Daya Bay NPP: 2 2.9 GWth Physics Symposium: Steve Kettell
BNL DB Activity in 2006 • Joined collaboration in February 2006 • Led (co-led) task forces: • Simulations: David Jaffe • Liquid Scintillator: Dick Hahn • Muon Veto: Laurie Littenberg • Antineutrino Detector: Steve Kettell • Lead role in preparation for the DOE Physics Review. • BNL hosted the Director's Review. • Proposal (DOE Physics Review): • leadership in drafting the Trigger/DAQ section • leadership of the Muon System section. • lead role in the coordination and drafting of the Installation, Operations and Project Development chapters and LS section. • lead role in editing and coordinating the Proposal. • Coordination of the US effort on the muon system and LS. • Coordination of the US design integration effort. • Lead role in drafting the successful US FY06 R&D proposal. Physics Symposium: Steve Kettell
Activity at BNL in 2007 • BNL scientists have key roles in the Daya Bay Project: • Chief Scientist: Steve Kettell • Chief Engineer: Ralph Brown • Muon System L2 Manager: Laurie Littenberg • Installation and Integration L2 Managers: Ralph Brown • Liquid Scintillator L3 Manager: Minfang Yeh • Analysis and Simulation Software L3 Manager: David Jaffe • Co-leader of International Simulation effort: David Jaffe • Co-leader of International Liquid Scintillator Task Force: Dick Hahn • CDR: • Chair of the Editorial Board and Editor-in-Chief: Steve Kettell • Members of the Editorial Board: David Jaffe and Laurie Littenberg • Technical advisor to the Editorial Board: Brett Viren • Lead Authors of 8 chapters: Steve Kettell, Laurie Littenberg, Ralph Brown. • Review committee: D. Jaffe, M. Bishai, B. Viren, R. Brown, L. Littenberg, D. Hahn. • BNL is playing a lead role, along with LBNL and IHEP in the engineering design and integration, including the Civil Design specification. • BNL is leading the effort to develop an installation plan • BNL is playing a lead role in developing a Daya Bay safety plan. Physics Symposium: Steve Kettell