Double Chooz Experiment and Applied Neutrino Physics
description
Transcript of Double Chooz Experiment and Applied Neutrino Physics
INPC2007-Tokyo Lhuillier David - CEA Saclay - France 1
Double Chooz Experiment Double Chooz Experiment and Applied Neutrino and Applied Neutrino
PhysicsPhysics
CEA Saclay : M. Cribier, T. Lasserre, A. Letourneau, D. Lhuillier, T. MuellerSUBATECH-NANTES: S. Cormon, M. Fallot, L.Giot, B. Guillon, J.
Martino, J.H. Xu
http://doublechooz.in2p3.fr/
Search for 13
• Simulation of e- and energy spectra• Applied physics: power measurement, non-proliferation
INPC2007-Tokyo Lhuillier David - CEA Saclay - France 2
PHASE 1 (2009-10) - Far detector only - sin2(213)<0.06 (1,5 years,90% C.L.) PHASE 2 (2011…) - Far + Near sites - sin2(213)<0.025 (3 years,90% C.L.)
2 identical 8.3t targets
flux Normalizati
on
@280m
oscillat
ion
@1050m
Double Chooz ExperimentDouble Chooz Experiment
2 PWR-N42x4.27 GWth
INPC2007-Tokyo Lhuillier David - CEA Saclay - France 3
€
e + p→ e+ + n
€
Gd* →Gd + γ ('s)
INPC2007-Tokyo Lhuillier David - CEA Saclay - France 4
Accurate Simulation of Accurate Simulation of Reactor Antineutrino Reactor Antineutrino
SpectraSpectra
• Determine normalization and shape for phase 1 (dominant error)
• Use near detector to validate studies of applied neutrino physics:
- Power measurement
- Non-proliferation
INPC2007-Tokyo Lhuillier David - CEA Saclay - France 5
Principle of our Principle of our ApproachApproach
Evolution code: MURE
fissilemat. + FY
neutron flux
Core geometry
isotope abundances
spectra database for all
isotopes
branch spectrum:BESTIOLE
nuclear database
exp. spectrum
models
Weighted
Total and e- energy spectra with complete error treatment
INPC2007-Tokyo Lhuillier David - CEA Saclay - France 6
Evolution Code MUREEvolution Code MUREMCNP 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
INPC2007-Tokyo Lhuillier David - CEA Saclay - France 7
Simulation of Chooz Simulation of Chooz ReactorsReactors
2 PWR - N42x4.27 GWth
Control rods (Instrumentation, Poisons…)
Zircalloy
205 Assembli
es264 rods
Fuel Assembly
(0.2x0.2x4.8m)Fuel rod
(D: 0.8 cm ; h:4.8 m)
Fuel UO2
pellets(2.1, 2.6, 3.1 % enrichment)
- Fuel: enriched Uranium - Moderator/Coolant: Light pressurized Water (155 Bar, 600K)
CPU limited, working on suitable sym. and approx.Full power and burn up info from electricity company during data taking
Core
INPC2007-Tokyo Lhuillier David - CEA Saclay - France 8
Building Total eBuilding Total e-- and and SpectraSpectra
•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.
dN/dE = n Yn(Z,A,t) i BRn,i P(E,E0i,Z)
Fission yields branching ratios for decay branch i with endpoint E0
i
shape
StrategyStrategy:
Reactor spectrum: Reactor spectrum: Sum of “n” isotopes of “i” branches
INPC2007-Tokyo Lhuillier David - CEA Saclay - France 9
P(E,E0i,Z)
Coulombcorrections
Phase space
Spectral Shape factorWell controlled for
allowed and forbidden unique transitions
. Sn(E)
E0=Ee+Efor each branch
info on all branches unambiguous conversion to spectrum
spectrum:
spectrum:
F(Z,E) . pE(E0i-E)2
Energy Energy SpectruSpectru
mm
INPC2007-Tokyo Lhuillier David - CEA Saclay - France 10
IntegralIntegralValidationValidation
electrone235U1.5 days
Agreement within 1up to 6 MeV
950 nuclei, ~10000 branchesValidation of spectrum shapeNo absolute normalization yet
INPC2007-Tokyo Lhuillier David - CEA Saclay - France 11
Error Error BarsBars
•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).
Good control of low energy part
[1.8-6] MeVRelevant fornormalization of phase 1
INPC2007-Tokyo Lhuillier David - CEA Saclay - France 12
Power MeasurementPower Measurement
€
Nν
= γ 1+ k(t)( )Pthermal
Burn up effect: Project of miniature detector based on
Double Chooz conceptTo be installed ~10m from reactor core
Unique tool for cross-calibration of reactor cores !
INPC2007-Tokyo Lhuillier David - CEA Saclay - France 13
NonNonProliferatiProliferati
onon235U 239Pu
E/fission 201.7 MeV 210.0 MeV
Mean energy
2.94 MeV 2.84 MeV
/fission > 1.8 MeV
1.92 1.45
<> for interaction
3.2 10-43 cm2
2.7 10-43 cm2
For a fixed thermal power, the measured e fluxes from pure 235U or 239Pu would differ by 55%…but realistic scenario implies tiny effect.
INPC2007-Tokyo Lhuillier David - CEA Saclay - France 14
ConclusionConclusion
•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
INPC2007-Tokyo Lhuillier David - CEA Saclay - France 15
Backup SlicesBackup Slices
INPC2007-Tokyo Lhuillier David - CEA Saclay - France 16
Double Chooz ConceptDouble Chooz Concept P
(e
e)
=
1-s
in2(2
13)s
in2(
m2 31
L/4
E)
Ne
ar
de
tect
or
Fa
r d
ete
cto
r
Disappearance experimentClean measurement
of 13
€
L m[ ] Eν = 3MeV( )
flux : 1021 e/s
Nuclear power station 2 cores: 4.27 GWth
Near detector ~280 m Far detector 1050 m
e e,,
€
m132 = 2.5 10-3 eV
3.0 10-3 eV
INPC2007-Tokyo Lhuillier David - CEA Saclay - France 17
Expected Oscillation Expected Oscillation SignalSignal
Far Spectrum
Near Spectrum
Far/Near ratio Far/Near ratio
sin2(213)=0.12
m2atm= 3.0 10-3 eV2
Aft
er 3
yea
rs
Assuming:
INPC2007-Tokyo Lhuillier David - CEA Saclay - France 18
Previous StudiesPrevious Studies
Theoretical approach : Klapdor & Metzinger microscopic calc. of trans. matrix elements (PLB82 + PRL82), Vogel et al. for 238U
Integral spectra measured 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 flux in agreement with Scheckenbach et al. + Vogel et al. for 238U, 1.9 % error on reactor e flux
INPC2007-Tokyo Lhuillier David - CEA Saclay - France 19
Exp. Spectra of Fission Exp. Spectra of Fission ProductsProducts
2211
•48 nuclei in perfect agreement with our database
•Remaining 63 replaced.
•Correct error estimate requires careful treatment of fit correlations
111 fission products measured by Tengblad’s et al at ISOLDE
INPC2007-Tokyo Lhuillier David - CEA Saclay - France 20
Bestiole Data Base
root and asciiformats
• 950 nuclei ~10000 branches 500 -n branches
• Interfaced to various sources of information
• tag all relevant info (forbiddenness, level of approx., …)
BDBBDB
INPC2007-Tokyo Lhuillier David - CEA Saclay - France 21
Electron spectra
Error BarsError Bars
•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)
Spectrum Shape
Quote preliminary ±2.5% sys. error
INPC2007-Tokyo Lhuillier David - CEA Saclay - France 22
Errors on all branches treated as independent…. Converges as
€
NBranches
Error Error BarsBars
•
• BR
From ENSDF nuclear database:
INPC2007-Tokyo Lhuillier David - CEA Saclay - France 23
Treatment of Treatment of CorrelationsCorrelations
€
χ 2 =Ri − Si( )
2
σ iR
( )2
+ σ iS
( )2
i
∑χ2 test of two independent data sets:
€
χ 2 = Ri − Si[ ]tVij
−1 Rj − Sj[ ]i, j
∑
€
Vij = Ri − Si( ) R j − S j( ) − Ri − Si R j − S j
€
Vij =VijR +Vij
S −VijRS −Vij
SR
Generalized χ2 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 (Pth, Y, BR, E0).
INPC2007-Tokyo Lhuillier David - CEA Saclay - France 24
Models for Unknown Models for Unknown spectraspectra
BESTIOLE + Tengblad et al.(JEF2.2) + Qbeta
approx
BESTIOLE +Tengblad et al. (JEF2.2) + Gross Theory from ENDFBVI, JENDL and JEFF3.1
INPC2007-Tokyo Lhuillier David - CEA Saclay - France 25
Pandemonium EffectPandemonium Effect
0
0
Z NA
Z-1N’A
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
det drops fast with E
+difficult analysis
of continuum
INPC2007-Tokyo Lhuillier David - CEA Saclay - France 26
Previous Power Previous Power MeasurementsMeasurements
INPC2007-Tokyo Lhuillier David - CEA Saclay - France 27
SONGSSONGS
San Onofre Nuclear Generating Station
Lawrence Livermore and
Sandia National Labs
Detector located in tendon gallery:
det ~ 10%
•469 evts/day
Evidencefor burn up effect (?)