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Double-CH  13  13 Z

Detailed overview of the Double-CHOOZ neutrino experiment, including detectors, scintillator development, sensitivities, and comparisons with other experiments. Analyzes expected events and simulation results. Provides insight into discovery potential and collaboration history.

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Double-CH  13  13 Z

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  1. Double-CH1313Z H. De Kerret (APC) On behalf the Double-Chooz proto-collaboration June 9 2004

  2. ne nx Best current constraint: CHOOZ e e (disappearance experiment) Pth= 8.5 GWth, L = 1,1 km, M = 5toverburden: 300 mwe R = 1.01  2.8%(stat)2.7%(syst) World best constraint ! @m2atm=2 10-3 eV2 sin22θ13 < 0.2 (90% C.L) M. Apollonio et. al., Eur.Phys.J. C27 (2003) 331-374

  3. e e,, The Double-CHOOZ concept D1 = 100-200 m D2 = 1050 m CHOOZ power station Near detector Far detector • anti-e flux (uranium 235, 238 & plutonium 239, 241) • Reaction: e + p  e+ + n, <E>~ 4 MeV, Ethresholdl =1.8 MeV • Dissapearance experiement • Search for a departure from the 1/D2 behavior

  4. CHOOZ site & Detector Overview e

  5. Double-Chooz, Ardennes, France Chooz-Near Chooz-Far Near site: D~100-200 m, overburden 50-80 mwe Far site: D~1.1 km, overburden 300 mwe V=2 x 12,67 m3, Dp=100-200m, Dl=1050m

  6. 250 m 125 m The CHOOZ-near site Near detector @100-200 m from the cores Exact position under study, in collaboration with EDF

  7. Correlations: - time :   30s- space 3e : < 1m3 • • Energy measurement of the e+, => En • Neutron capture on Gd, ED≈8 MeV Detect the antineutrino e + p  e+ + n The target is the active medium : - liquid scintillator loadedat ≈ 0.1 % en Gd Important progress from LENS

  8. The CHOOZ-near detector ~10-20 m Dense material ~5- 15 m

  9. Detector design • A scintillating buffer around the target (to see the gammas from positron capture and Gd decays) ~60 cm • A non scintillating buffer in front of pmts (reduce the single rates) ~ 1m • A muon veto • Increase as much as possible the active buffer for the fast neutrons coming from outside

  10. The CHOOZ-far detector shielding: 0,15m steel 7 m  target:80% dodécane + 20% PXE + 0.1% Gd (acrylix, r=1,2m, h = 2,8m, 12,7 m3) -catcher: 80% dodécane + 20% PXE (acrylique, r+0,6m – V= 28,1 m3) 7 m non-scintillating buffer: same liquid (+ quencher?) (r+0.95m, , V=100 m3) 7 m PMTs supporting structure Muon VETO: scintillating oil (r+0.6 m – V=110 m3) Existing pit

  11. Scintillator Overview

  12. R-COO- 3+Gd 3+Gd R-COO- (R-COOH)x -OOC-R Gd-Acac Gadolinium doped scintillator • Goal: 0.1% Gd loaded scintillator Light yield ~8000 /MeV + attenuation length > 5m STABLE Compatible with acrylic • R&D LENS 1998-2004 • Carboxylate based scintillator • Beta dikitonates based scintillator Carboxylate

  13. Scintillator development Gd-ACAC • Baseline • PC (C9H12), PXE (C16H18) attack acrylics • Dodécane + PXE more resistant … • R&D Saclay+MPIK+Gran Sasso (08/2004) • Flours concentration • Match scintillation light to PMTs • PPO : 6g/l • BisMSB: 20mg/l Baseline: 80% dodecane + 20% PXE + 6 g/l PPO + 20 mg/l BisMSB + 0.1% Gd LY~8000 /MeV , L = 5-10 meters

  14. Scintillator R&D • R&D 1/ Long term stability  2004 2/ scintillator-acrylic compatibility • Ageing test @50o (Saclay , Gran Sasso/INR, MPIK) • Material compatibility test (Saclay , MPIK) • Saclay  acrylic envelop design in progress First ageing test @40o, 50o (Caroxylates, Gran Sasso / INR) (scintillator tests, Saclay)

  15. Sensitivity &Discovery Potential

  16. Description of the simulation Analyse standard Expected events / bin i: NiA( sin2(213)gen ) Tested spectrum OiA: Theoretical prediction : TiA= (1 + a + bA + ci) x NiA( sin2(213)rec)

  17. 90% C.L. sensitivity if sin2(213)=0 m2=2.0 10-3 eV2 3 years (efficiency included) sin2(213)<0.03 m2=2.4 10-3 eV2 3 years (efficiency included) sin2(213)<0.024

  18. Relative normalisation error m2=2.0 10-3 eV2 3 years (efficiency included)

  19. Influence of flat backgrounds Th. Lasserre

  20. Influence of the shape error Th. Lasserre

  21. Lindner’s analysis of Double-CHOOZ sensitivity

  22. 340 tons, 3 years 12.7 tons, 3 years P. Huber et. al. hep/0403068 Lindner’s analysis of Double-CHOOZ sensitivity e

  23. P. Huber et. al. hep/0403068 Attempt to compare Double-Chooz with Beams & Superbrams m2=2.0 10-3 eV2 Double-CHOOZ starts with two detectors on 01/01/2008 T2K starts at FULL intensity on 01/01/2010

  24. e oscillation @Double-CHOOZ @1,05 km e

  25. Spectrum deformation @Double-CHOOZ sin2(213)=0.15

  26. Double-CHOOZ discovery potential Th. Lasserre

  27. Double-CHOOZ discovery potential

  28. CompareDouble-Chooz & T2K (limite @90% C.L.) I

  29. sin22θ13 = 0.08 sin22θ13 = 0.14 sin22θ13 = 0.04 Attempt to compare Double-Chooz with T2K (3σ discovery potential)

  30. Energy scale Energy scale modified on both detectors by +1% Use a 1 parameter fit for all the rest q13(fit) Strong distortion q13(gen)

  31. Moving the Close detector by +0.5m Distance to reactor increases Dist to Far decreases Position of the near detector

  32. First day 235U day 330 q (fit) 239Pu 238U 241Pu q (gen) Burn-up effect (330 days fuel evolution)

  33. Proto-collaboration, Letter of Intentand prospects e

  34. The current proto-collaboration Chooz, November 2003 • Double-CHOOZ meetings • Chooz, November 2003 • Heidelberg, February 2004 • Tubingen, April 2004

  35. Letter of Intent

  36. Double-Chooz & IAEA • IAEA :Intenational Agency for Atomic Energy • Missions: Safety & Security, Science & Technology, Safeguard & Verification • Control that member states do no use civil installations with military goals (production of plutonium !) • Control of the nuclear fuel in the whole fuel cycle * Fuel assemblies, rods, containers *(*Anti-neutrinos could play a role!) Distant & unexpected controls of the nuclear installations * • Why IAEA is interested to antineutrino ? • IAEA wants the « state of the art »methods for the future ! • Several futuristic methods under study Kr, I, Cs gas trace in atmosphere • Cost issue … • AIEA wants a feasibility study on antineutrinos - Monitoring of the reactors with a Double-Chooz like detector ? - Monitoring a country – new reactors “à la KamLAND” • CEA/Saclay  we already ask some support for: - Double-Chooz near detector - New nuclear physics program to improve knowledge of reactor  spectrum

  37. Improving CHOOZ– Statistical error - @CHOOZ: R = 1.01  2.8%(stat)2.7%(syst) • increase luminosity L = t x P(GW) x Vcible

  38. Improve CHOOZ– Systematic error - • @CHOOZ : σsys=2.8% • Decrease the total systematic error • Detector design • 2 identical detectors  vers σrelative sys~0,6% • Background – improve S/B>100  error<1%

  39. Detector simulation&calibration

  40. Photons tracking • 2 simulation indépendantes • PCC & APC  simulation de CHOOZ (GEANT3) • Kurchatov  simulation Borexino (GEANT4)

  41. Photons tracking • 20% PXE + 80% dodécane + 0.1% Gd + 6g/l PPO + 20mg/l BisMSB • ~200 p.e./MeV with 500 PMTs – reflection coef =0% • Les PMs 8’’ are within the buffer ( glass at 25 cm inside)  Light collection ~flat (+5% maxi. in the target)

  42. Systematic errors

  43. Same batch of scintillator for both detectors Systematic error; « reactor » type Systematic errors: « detector » type M. Apollonio et. al., Eur.Phys.J. C27 (2003) 331-374

  44. Fast signal: positron scintillanting buffer Non scintillating Buffer Ee+ (MeV) Ee+ (MeV) • CHOOZ : only scintillanting buffer • Detector = calorimter : positron energy isfully contained • Butaccidental rate high threshold on e+, many analysis cuts • Double-CHOOZ : 1 Scintillanting buffer (60cm) + 1 Non-scintillanting buffer (95cm) • Reduce the PMTs noise (40K,Tl) • Eseuil hardware ~500 keV  No more thrshold cut 0% systematic ! • 1.022 MeV calibration point at e+ spectrum start ( ) • BDFs measuremnt above and below the positiron spectrum

  45. Delayed signal : neutron Non scintillating buffer Scintillating buffer Gd Gd H H En (MeV) En (MeV) (H. de Kerret) • Gadolinium loaded scintillator (~0.1%) • Gd  8 MeV ’s (capture on Gd : 86.6%1.0% in CHOOZ, Eur.Phys.J. C27 (2003) 331-374) • H  2.2 MeV ’s • n capture prob. 1.0% (CHOOZ)  O% with 2 detectors (MC uncertainty) • t (e+-n)  0.4% (CHOOZ)  0% with 2 detectors (MC uncertainty) • n energy 0.4% (CHOOZ)  Scintillating buffer mandatory(as in CHOOZ) • “spill in / spill out” effect  1.0% (CHOOZ)  O(0.1%) 2 identical detectors needed!  But neutronics to be checked

  46. Analyis cuts @CHOOZ M. Apollonio et. al., Eur.Phys.J. C27 (2003) 331-374 Analysis cuts @Double-CHOOZ

  47. All systematic errors in Double-Chooz

  48. R&D on systematic errors in 2004 • Dead time(Heidelberg) - important (~50%) but simple (500microsec/muon) - generate couples of test particles et measure their survival time - hardware tests in 2004 • Quantity of liquid in the target(Saclay) - build both targets in factory in the same time + test filling - geometrical measurements in factory and on site - weight liquids in the same intermdiate tank  0.1% • Distance detector-reactor core(APC-Saclay ph.nucl.+Subatech?) -10cm a 150 m 0.15% systematic error - 10cm in Chooz pub. (+- 3cm at Bugey) - core center of gravty movement of 6cm monitored at bugey

  49. Background

  50. Reduce backgrounds • CHOOZ: S/B ~ 25 • Double-CHOOZ aim: S/B>~100 • Double-CHOOZ-far (300 mwe): 12.7 m3 Signal x ~3 • Accidentals: • Buffer non scintillanting buffers • Double-Chooz: B/3  less than 0.5% and measurable • correlated events: • CHOOZ: ~1 recoil proton / day & signal =26/d • Double-CHOOZ: S* 2.3 & B/2  S/B>100 (neutronn simulation in progress) • Double-CHOOZ-near (~60 mwe): Signal x 50-100 SCHOOZ-loin • -Dproche ~100-200m  Signal * >30, but * 30 • - all backgrounds: • BDF CHOOZ-loin *<30  S/B > 100 •  Measure all BDFs at 50%

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