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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. - PowerPoint PPT Presentation
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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
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-loaded scintillator
Gd-loaded scintillator
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
current bound (Chooz + 3 constraint)
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
current bound (Chooz + 3 constraint)
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