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Double Chooz Experiment and Applied Neutrino Physics

Double Chooz Experiment and Applied Neutrino Physics. http://doublechooz.in2p3.fr/.  Search for  13 Simulation of e - and  energy spectra Applied  physics: power measurement, non-proliferation. CEA Saclay : M. Cribier, T. Lasserre, A. Letourneau, D. Lhuillier, T. Mueller

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Double Chooz Experiment and Applied Neutrino Physics

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  1. Double Chooz Experiment and Applied Neutrino Physics http://doublechooz.in2p3.fr/ • Search for 13 • Simulation of e- and  energy spectra • Applied  physics: power measurement, • non-proliferation • CEA Saclay :M. Cribier, T. Lasserre,A. Letourneau, D. Lhuillier, T. Mueller • SUBATECH-NANTES: S. Cormon, M. Fallot, L.Giot, B. Guillon, J. Martino, J.H. Xu Lhuillier David - CEA Saclay - France

  2. Double Chooz Experiment  oscillation @1050m 2 identical 8.3t targets  flux Normalization @280m • PHASE 1 (2009-10) • - Far detector only • - sin2(213)<0.06 • (1,5 years,90% C.L.) • PHASE 2 (2011…) • - Far + Near sites • - sin2(213)<0.025 • (3 years,90% C.L.) 2 PWR-N4 2x4.27 GWth Lhuillier David - CEA Saclay - France

  3. Lhuillier David - CEA Saclay - France

  4. Accurate Simulation of Reactor Antineutrino Spectra • Determine normalization and shape for phase 1 (dominant error) • Use near detector to validate studies of applied neutrino physics: - Power measurement - Non-proliferation Lhuillier David - CEA Saclay - France

  5. exp. spectrum fissile mat. + FY nuclear database models neutron flux Core geometry isotope abundances Principle of our Approach • branch spectrum: BESTIOLE Evolution code: MURE  spectra database for all isotopes Weighted  Total  and e- energy spectra with complete error treatment Lhuillier David - CEA Saclay - France

  6. Evolution Code MURE MCNP Utility for Reactor Evolution • Neutron flux automatically adjusted to total power parameter • Evolution equations and time step sizes validated, propagation of fission yield error • Account for neutron capture • (V. Kopeikin et al., Phys. Atom. Nucl. 67 (2004) 1963) • Working on the geometry of a N4 reactor core Lhuillier David - CEA Saclay - France

  7. Simulation of Chooz Reactors • - Fuel: enriched Uranium • - Moderator/Coolant: Light pressurized Water (155 Bar, 600K) 2 PWR - N4 2x4.27 GWth Fuel Assembly Core Fuel rod (0.2x0.2x4.8m) (D: 0.8 cm ; h:4.8 m) 205 Assemblies 264 rods Zircalloy Fuel UO2 pellets (2.1, 2.6, 3.1 % enrichment) Control rods (Instrumentation, Poisons…) CPU limited, working on suitable sym. and approx. Full power and burn up info from electricity company during data taking Lhuillier David - CEA Saclay - France

  8. Building Total e- and  Spectra Reactor spectrum: Sum of “n” isotopes of “i”  branches dN/dE = SnYn(Z,A,t)SiBRn,iP(En,E0i,Z) branching ratios for decay branch i with endpoint E0i shape Fission yields Strategy: • Collect all available exp. info on individual  branches • Remaining short-lived, high Q, nuclei described by nuclear models. • Propagate all errors and compute correlations for any combination of fissile materials and any irradiation time. • Final cross-check with integral measurements. Lhuillier David - CEA Saclay - France

  9. Energy Spectrum  spectrum: P(E,E0i,Z)  F(Z,E) . pE(E0i-E)2 . Sn(E)  spectrum: Phase space E0=Ee+Efor each  branch Coulomb corrections Spectral Shape factor Well controlled for allowed and forbidden unique transitions info on all b branches • unambiguous conversion to  spectrum Lhuillier David - CEA Saclay - France

  10. e electron IntegralValidation 235U 1.5 days Agreement within 1 up to 6 MeV 950 nuclei, ~10000  branches Validation of spectrum shape No absolute normalization yet Lhuillier David - CEA Saclay - France

  11. Error Bars Good control of low energy part [1.8-6] MeV Relevant for normalization of phase 1 • Expect final error bar comparable to integral data: BR, E0,Shape included, working on fission yields error • Computation of correlations on progress • -->Significant gain in sensitivity to shape distortions because most errors induce large correlations (Pth, Y, BR, E0). Lhuillier David - CEA Saclay - France

  12. Power Measurement Burn up effect: Project of miniature detector based on Double Chooz concept To be installed ~10m from reactor core Unique tool for cross-calibration of reactor cores ! Lhuillier David - CEA Saclay - France

  13. NonProliferation For a fixed thermal power, the measured e fluxes from pure 235U or 239Pu would differ by 55%… but realistic scenario implies tiny effect. Lhuillier David - CEA Saclay - France

  14. Conclusion • Promising preliminary results for normalization of Double Chooz phase 1. • -Original approach with complete treatment of error bars and their correlations (expected to be large) • Same simulation package is a key element of future applied  physics: • -Project of 2-3%power measurement with miniature detector • -non-proliferation. Looks difficult, first goal is to determine detection threshold for removed Pu mass and point out critical unknown nuclei to increase sensitivity Lhuillier David - CEA Saclay - France

  15. Backup Slices Lhuillier David - CEA Saclay - France

  16. Double Chooz Concept Nuclear power station 2 cores: 4.27 GWth Near detector ~280 m Far detector 1050 m e e,, flux : 1021e/s Disappearance experiment Clean measurement of 13 Near detector P(e e) = 1-sin2(213)sin2(m231L/4E) Far detector 2.5 10-3 eV 3.0 10-3 eV Lhuillier David - CEA Saclay - France

  17. Expected Oscillation Signal Assuming: Far Spectrum m2atm= 3.0 10-3 eV2 sin2(213)=0.12 After 3 years Near Spectrum Far/Near ratio Lhuillier David - CEA Saclay - France

  18. Previous Studies • Theoretical approach:Klapdor & Metzinger microscopic calc. of trans. matrix elements (PLB82 + PRL82), Vogel et al. for 238U • Integral b-spectrameasured by Schreckenbach et al. (at better than 2% until 8 MeV) & Hahn et al. @ILL 235U, 239,241Pu targets, (PLB218(1989)365) but conversion : global fit including 30 arbitrary contributions: global shape uncertainty from 1.3%@3MeV to 9%@8MeV • FP contributions :measurements of Tengblad et al. (NPA503(1989)136) 111 nuclei @ISOLDE don’t agree with the experimental integral spectra (important errors : 5% at 4MeV, 11% at 5MeV and 20% at 8MeV) • Chooz and Bugey :energy spectrum and fluxin agreement with Scheckenbach et al. + Vogel et al. for 238U, 1.9 % error on reactor ne flux Lhuillier David - CEA Saclay - France

  19. 1 1 2 2 Exp. Spectra of Fission Products 111 fission products measured by Tengblad’s et al at ISOLDE • 48 nuclei in perfect agreement with our database • Remaining 63 replaced. • Correct error • estimate requires • careful treatment • of fit correlations Lhuillier David - CEA Saclay - France

  20. BDB Bestiole Data Base root and ascii formats • 950 nuclei • ~10000  branches • 500 -n branches • Interfaced to various sources of information • tag all relevant info (forbiddenness, level of approx., …) Lhuillier David - CEA Saclay - France

  21. Electron spectra Error Bars Spectrum Shape • Requires spin and parity of nuclear levels • No predictions for non-unique transitions • Use envelop of illustrated shapes to determine error • (extra info from exp. shape factors) Quote preliminary ±2.5% sys. error Lhuillier David - CEA Saclay - France

  22. Error Bars From ENSDF nuclear database: •  • dBR • Errors on all branches treated as independent…. • Converges as Lhuillier David - CEA Saclay - France

  23. Treatment of Correlations 2 test of two independent data sets: Generalized 2 test with correlated errors: , Adapted to different studies: -Oscillations: data (R) vs simul (S) -Non prolif: simul vs simul Numerically computed Expect large gain in sensitivity to shape distortions because most errors induce large correlations (dPth, dY, dBR, E0). Lhuillier David - CEA Saclay - France

  24. BESTIOLE +Tengblad et al. (JEF2.2) + Gross Theory from ENDFBVI, JENDL and JEFF3.1 BESTIOLE + Tengblad et al.(JEF2.2) + Qbeta approx Models for Unknown  spectra Lhuillier David - CEA Saclay - France

  25. Pandemonium Effect   0 A Z N det drops fast with E + difficult analysis of continuum  0 A Z-1N’ • If not included in database: • - Underestimation of the low E part of the spectrum w.r.t. high energy part • - Tengblad’s measurement, not sensitive to pandemonium, partly correct for this effect Lhuillier David - CEA Saclay - France

  26. Previous Power Measurements Lhuillier David - CEA Saclay - France

  27. SONGS San Onofre Nuclear Generating Station • Detector located in tendon gallery: • det~ 10% • 469 evts/day Lawrence Livermore and Sandia National Labs Evidence for burn up effect (?) Lhuillier David - CEA Saclay - France

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