physics symposium: steve kettell10/2/20071 the daya bay reactor antineutrino experiment steve...

Physics Symposium: Steve Kettell

10/2/2007 1

The Daya Bay Reactor Antineutrino Experiment

Steve KettellBNL

1) Why Daya Bay?2) Status/BNL involvement


10/2/2007 2

?

The Last Mixing Angle: 13

UMNSP MatrixMaki, Nakagawa, Sakata, Pontecorvo

Motivations to measure 13 • Key to leptonic CP violation. • How to extend the SM?

• What ise fraction of 3?• Is there symmetry in mixing?

U Ue1 Ue2 Ue3

U1 U2 U 3

U1 U 2 U 3

0.8 0.5 Ue3

0.4 0.6 0.7

0.4 0.6 0.7

?

1 0 0

0 cos23 sin23

0 sin23 cos23

cos13 0 e iCP sin13

0 1 0

e iCP sin13 0 cos13

cos12 sin12 0

sin12 cos12 0

0 0 1

1 0 0

0 e i / 2 0

0 0 e i / 2i

atmospheric, K2K, MINOS reactor and acceleratorMINOS, Double Chooz Daya Bay

0SNO, solar SK, KamLAND

12~32° 23~45° 13<12°


10/2/2007 3

Measuring sin2213 with Reactor Antineutrinos

~1.8 km

~ 0.3-0.5 km

Daya Bay, China

Pee 1 sin2 213 sin2 m312L

4E

cos4 13 sin2 212 sin2 m21

2L

4E

Distance (km)P

e e

nuclear reactor

detector 1detector 2

13

• No dependence on CP or matter effects• Cost effective• Rapid deployment

sin22 = 0.1

e

disappearance probability


10/2/2007 4

sin22 < 0.17 (m231 = 2.5 103 eV2)

Daya Bay Strategy for 13

Limit on from Chooz

Daya Bayprojecteduncertainty!Chooz Daya

Bay

events 3000/335d 230k/3yr

Mass 5 ton 80 ton

Sys. Err 2.7% 0.2%


10/2/2007 5

Daya Baycores

Ling Aocores

Ling Ao IIcores(under

construction)

Daya Baynear

Ling Ao near

Far

LShall

Entrance

Construction tunnel

Waterhall

liquid scintillatormineral oil

Gd-LS

Water shield

Antineutrino Detector

4x20 ton (far)


10/2/2007 6

• 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 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

Daya Bay @ BNL


10/2/2007 7

Sensitivity

3-year run with 80 t at far site

Daya Baynear hall

(40 t)

Tunnel entrance

Ling Aonear hall

(40 t)

Far hall(80 t)

• Rate and spectral shapeRate and spectral shape• Relative detector systematic error of Relative detector systematic error of 0.2%0.2%

sin2213<0.01 (90% CL) over allowed m2

90% C.L.

Reactor pairs

Currently allowed range of m2


10/2/2007 8

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


10/2/2007 9

Summary

•The measurement of 13 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)


10/2/2007 10

Backup


10/2/2007 11

Daya Bay collaboration

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.

Europe (3) (9)

JINR, Dubna, Russia

Kurchatov Institute, Russia

Charles University, Czech Republic

~ 145 collaborators


10/2/2007 12

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


10/2/2007 13

• inverse -decay in Gd-doped liquid scintillator:

Arb

itra

ry

Flux Cross

Sectio

n

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

E Te+ + Tn + (mn - mp) + me+ Te+ + 1.8 MeV

• Time- and energy-tagged signal is a good tool to suppress background events.

• Energy of e is given by:

10-40 keV

0.1% Gd


10/2/2007 14

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


10/2/2007 15

Antineutrino Detector

• 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:

11.6%12.5cm

liquid scintillator mineral oil

Gd-LS

Water shield


10/2/2007 16

• Muon Veto - suppress spallation

neutrons - require 99.5% efficiency• Water shield (2.5m) - rock neutrons - radioactivity

Muon System

•Water Cherenkov detectors with963 PMTs in 3 sites•756 RPC chambers over top of 3 pools (6048 readout strips)


10/2/2007 17

Ling Ao II NPP:2 2.9 GWth

Ready by 2010-2011

Ling Ao NPP:2 2.9 GWth

Daya Bay Nuclear Power Facilities

Daya Bay NPP:2 2.9 GWth

1 GWth generates 2 × 1020 e per sec

• 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)


10/2/2007 18

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.


10/2/2007 19

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 kettell10/2/20071 the daya bay reactor antineutrino experiment steve...

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