Future Reactor and Solar Neutrino Facilities

Future Reactor and Solar Neutrino Facilities

S. Biller, Oxford University

near

Reactor Experiments

(13)

νe

νe

νe

νe

νe

νe

Distance

Pro

babi

lity

ν e

1.0

EEνν ≤ 8 MeV≤ 8 MeV

Well understood, isotropic source Well understood, isotropic source of electron anti-neutrinosof electron anti-neutrinos Oscillations observed as Oscillations observed as

disappearancedisappearance of of ννee

sinsin2222θθ1313

Survival ProbabilitySurvival Probability

+ O(m122 / m13

2)

No 23 ambiquity; No CP effects; No matter effects; Minimal dependence on m122

Reactor Neutrinos

P(e e)1 sin2 213 sin2(1.27m13

2 L /E )

Another Reason for Multiple Approaches:

These measurements are difficult! So, it’s important to have independentmeasurements with comparable sensitivities using approaches with different systematics

Braidwood

Angra

Double Chooz

Daya Bay

Reno

KASKA

Krasnoyarsk

Diablo Canyon

Comparison of Reactor Neutrino Experiments

Experiments Location

Thermal Power

(GW)

Distances

Near/Far

(m)

Depth

Near/Far

(mwe)

Target Mass

(tons)

Double-CHOOZ France 8.7 415/1050 114/300 10/10

RENO Korea 17.3 290/1380 120/450 15/15

Daya Bay China 11.6 360(500)/1985(1613) 260/910 80/80

e+pn

e+

Gd-loaded scintillator

Gd*

BackgroundsBackgroundsThere are two types of background…There are two types of background…

1.1. Uncorrelated Uncorrelated − Two random events that occur close together − Two random events that occur close together in space and time and mimic the parts of the coincidence.in space and time and mimic the parts of the coincidence.

This BG rate can be estimated by measuring the singles rates, This BG rate can be estimated by measuring the singles rates, or by switching the order of the coincidence events.or by switching the order of the coincidence events.

2.2. Correlated − One event that mimics both parts of the Correlated − One event that mimics both parts of the coincidence signal.coincidence signal.

These may be caused by fast neutrons (from cosmic These may be caused by fast neutrons (from cosmic ’s) that ’s) that strike a proton in the scintillator. The recoiling proton mimics strike a proton in the scintillator. The recoiling proton mimics the the ee++ and the neutron captures. and the neutron captures.

Or they may be cause by muon produced isotopes like Or they may be cause by muon produced isotopes like 99Li and Li and 88He which sometimes decay to He which sometimes decay to ββ++n.n.

Estimating the correlated rate is much more difficult!Estimating the correlated rate is much more difficult!

n

p

n

e+pn

e+



Gd*

Double Chooz detector concept (adopted by all)

7 m

Steel Shielding

7 m

Muon VETO: scintillating oil

Non-scintillating buffer oil

-catcher: 80% dodecane + 20% PXE

Buffer stainless steel tank + 400 PMTs (10’)

target: 80% dodecane + 20% PXE + 0.1% Gd

n

ep

Gd

~ 8 MeV

511 keV

511 keVe+

• Mechanically complex construction• Asymmetric• Difficult to calibrate

• Necessity unclear for 2 position measurement• Untested

Double Chooz

Chooz Nuclear Power PlantNorthern France

2 units with thermal output of 8.7 GW

Far Detector:L = 1050 m300 mwe~50 events/day

Near Detector: <L> = 415 m210 mwe~550 events/day

Reactor cores

(Sussex)

Near detector Far detector

Improving CHOOZ results

@CHOOZ: R = 1.01 2.8%(stat) 2.7%(syst)

CHOOZ-far : 50 000/3 yCHOOZ-near: ~1 106/3 y2700Event rate

3-5 yearsFew monthsData taking period

0,5%2,7%Statistical error

6,82 1028 H/m36,77 1028 H/m3 Target composition

10,2 m35,55 m3Target volume

Double-ChoozCHOOZ

– Statistical error –

– Systematic error –

Luminosity incerase L = t x P(GW) x Np

No reconstruction cut on fiducial volumeMore uniform detection efficiency

Relative measurement using 2 “identical” detectors

Continuously monitor detector stability

Calibrate relative PMT timing

Study optical characteristics at different wavelengths

Provides a simple, adaptablesystem for non-intrusive, in situcalibration with elements fixedin a well-defined, stable geometry

SoI fromSussex recentlysubmitted

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

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.

Europe (3)

JINR, Dubna, Russia

Kurchatov Institute, Russia

Charles University, Czech Republic

~ 160 collaborators

Experimental Layout Far site1615 m from Ling Ao1985 m from Daya BayOverburden: 350 m

Ling Ao Near site~500 m from Ling AoOverburden: 112 m

Daya Bay Near site363 m from Daya BayOverburden: 98 m

9/14/2007 TAUP 2007, Sendai 22

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)

E/E = 12%/E r = 13 cm

AD modules in far site

Muon veto detector designMultiple muon veto detectors:

RPC’s at the top as muon trackerWater pool as Cherenkov counter has inner/outer regionsCombined eff.

> (99.5 0.25) %

Reactor Experiment for Neutrino Oscillation

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

Schematic Setup of RENO at YongGwang

Far Detector

Near Detector

Tunnel Length 300 m

Tunnel Length 100 m

1.4 km

200 m Mt.

70 m Hill

Schematic View of Underground FacilitySchematic View of Underground Facility

Experimental Hall

Access Tunnel

Detector

(4m high ☓ 4m wide)

100m 300m

70m high

200m high

1,380m

290m

Far Detector

Near Detector

RENO Detector

Dimensions

Target-

catcher

BufferVeto

Inner Diameter (cm)

Inner Height (cm)

Filled with

Mass (tons)

Target Vessel

280 320 Gd(0.1%) + LS

15.4

Gamma catcher

400 440 LS 27.5

Buffer tank

540 580 Mineral oil

59.2

Veto tank

740 780 water 201.8

total ~300 tons

13 limit from global analysisT. Schwetz hep-ph/0606060T. Schwetz hep-ph/0606060

sin2 213 < 0.11 @ 90% CL

2008 2009 2010 2011 2012 2013 2014 2015

0.10

0.09

0.08

0.07

0.06

0.05

0.04

0.03

0.02

0.01

sin2

(2 1

3)

sen

sitiv

ity a

t 90

% C

.L.

current bound (Chooz + 3 constraint)

Double Chooz

RENO

Daya Bay

2008 2009 2010 2011 2012 2013 2014 2015

0.10

0.09

0.08

0.07

0.06

0.05

0.04

0.03

0.02

0.01

sin2

(2 1

3)

sen

sitiv

ity a

t 90

% C

.L.

Double Chooz

RENO

Daya Bay

T2K


2008 2009 2010 2011 2012 2013 2014 2015

0.10

0.09

0.08

0.07

0.06

0.05

0.04

0.03

0.02

0.01

Double Chooz

RENO

Daya Bay

T2K

sin2

(2 1

3)

sen

sitiv

ity a

t 3

det

ectio

n le

vel


E-776 Savannah River

Bugey E-816

1) Redundancy

2) Redundancy

Solar Experiments

(near term)

Limit on 13 under 3 scenario at level of ~0.1 in sin2213

PeeSNO sin212cos413

(MSW) PeeKL (1 0.39sin2212)cos413

(Vac)

Robertson nucl-ex/0602005; Fogli et al hep-ex/0506083

Present:12 and m12

2 determined by SNO, KamLAND (KL) and S-K.

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 , and S34

Very Near Future:

Push to lower energies (LETA, SK III) and reduced errors

Limit will improve somewhat due to more accurate constraints from SNO, Kamland and Borexino

Improved constraints should appear soon

• CNO gives information on age of Globular Clusters

Next Goals:

pep & CNO neutrinos

• pp and pep fluxes direct test of luminosity constraint

• pep at 1.4 MeV probes MSW upturn at low energies, tests for non-standard interactions

• Generally important to measure fundamental processes

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 sensitivity

goal: 105 to 106 reduction

• 2092 meters deep underground

• 1000 tons of ultrapure D2O in a 12 meter diameter acrylic vessel

• 7000 tons of ultrapure H2O as shield

• 9500 PMTs mounted on a 18 meter diameter frame

• electronics, DAQ, understanding of our detector

Alread

y Exi

sts

! SNO+

• 1000 tons of ultrapure liquid scintillator in a 12 meter diameter acrylic vessel

SNO

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

(first phase)

SNO+ CollaborationQueen’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 AlbertaA. Hallin, C. Krauss

Carleton UniversityK. Graham

Laurentian UniversityD. Hallman, C. Virtue

SNOLABB. Cleveland, F. Duncan, R. Ford, N. Gagnon, J. Heise, C. Jillings, I. Lawson

Brookhaven National LaboratoryR. Hahn, M. Yeh, Y. Williamson

Idaho State UniversityK. Keeter, J. Popp, E. Tatar

University of PennsylvaniaG. Beier, H. Deng, B. Heintzelman, J. Klein, J. Secrest

University of WashingtonN. Tolich, J. Wilkerson

University of DresdenK. Zuber

LIP LisbonS. Andringa, N. Barros, J. Maneira

University of SussexS. Peeters

University of OxfordS. Biller, N, Jelley, J, Wilson

SNO+ AV Hold Down

ExistingAV SupportRopes

SNO+ AV Hold Down

AV Hold DownRopes

ExistingAV SupportRopes

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 isalready smaller than the signal and one can still tag and veto

SNO+ pep Solar Neutrino Signal

3600 pep events/(kton·year), for electron recoils >0.8 MeV

• 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

SNO+ Double Beta Decay

150Nd• 3.37 MeV endpoint• (9.7 ± 0.7 ± 1.0) × 1018 yr

2half-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

table from F. Avignone Neutrino 2004

• 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…

Nd-Loaded Scintillator

0: 1000 events peryear with 1% naturalNd-loaded liquidscintillator in SNO+

Test <m> = 0.150 eV

maximum likelihood statistical test of the shape to extract 0 and 2 components…~240 units of 2 significance after only 1 year!

Klapdor-Kleingrothaus et al., Phys. Lett. B 586, 198, (2004)

simulation:one year of data

• at 1% loading (natural Nd), there is too much light absorption by Nd– 47±6 pe/MeV (from Monte

Carlo)

• at 0.1% loading (isotopically enriched to 56%) our Monte Carlo predicts– 400±21 pe/MeV

Light Output and Concentration

Nd-150 Consortium

• SuperNEMO and SNO+, MOON and DCBA are supporting efforts to maintain an existing French AVLIS facility that is capable of making 100’s of kg of enriched Nd– a facility that enriched 204 kg of U (from

0.7% to 2.5%) in several hundred hours

Statistical Sensitivity in SNO+

500 kg isotope 56 kg isotope

• 3 sigma detection on at least 5 out of 10 fake data sets• 2/0 decay rates are from Elliott & Vogel, Ann. Rev. Nucl. Part. Sci. 52, 115 (2002)

corresponds to 0.1% natural Nd LSin SNO+

SNO+ Nd Broadbrush Schedule

• end of 2009: fill and run with pure scintillator

• 2010: add Nd

• 2011: below 100 meV sensitivity reached if natural Nd and below 50 meV reached if enriched Nd

SNO+ Project Grant Review for NSERC GSC-19 (January, 2008)

Executive Summary

The physics reach of SNO+ is outstanding. SNO+ can be one of the first experiments to test the evidence for neutrinoless double decay that was reported by Klapdor et al. and can obtain the world’s best sensitivity for this process after several years of data taking...

In addition, SNO+ has the potential of making a precision measurement of the pep solar neutrino flux ( ∼ 5%), which would enable a search for physics beyond the Standard Model...

Overall, the review committee endorses the plan to go “full speed ahead”

2008-09: $1M unconditional; $300k conditional on external engineering review of the final AV hold down design, to take place this summer.

2009-10: $800k unconditional; $500k capital funding conditional on CFI approval of the SNO+ capital request.

Physicists evaluatingUK funding landscape

Plan to submit SoI in a few months

• No Common Fund• No M & O• No major hardware purchase (“We already gave”)

STFC

VERY inexpensive way to capitalise on previous UK investmentand still have extremely high impact doing world-leading physics

Future Reactor and Solar Neutrino Facilities

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