REACTOR ANTINEUTRINO ENERGY SPECTRA IN THE
FRAME OF FUNDAMENTAL AND APPLIED NEUTRINO
PHYSICS.
M. Fallot1 1 ERDRE group, SUBATECH (CNRS/IN2P3, Ecole des Mines de Nantes, Université de Nantes), 4, rue A. Kastler, 44307 Nantes cedex 3, France fallot@subatech.in2p3.fr FISSION 2013, Caen, France
Outline
  Introduction
  Summation Method for Antineutrino Energy Spectrum
  New Conversion Method of Integral Beta Spectra and New Converted
Spectra
  On the Nuclear Data Side: Synergy with Decay Heat, Pandemonium
Effect, Total Absorption Spectroscopy Technique
  On the Particle Physics Side: some Sterile Neutrino Experiments
  Reactor Experiments in France: Nucifer, STEREO and SoLid
  Conclusions and Outlooks
2
Reactor monitoring with antineutrinos
235U
239Pu
Ef (MeV)
201.9
210.0
<Eν > (MeV)
1.46
1.32
<Nν>
(E>1.8MeV)
5.58
(1.92)
5.09
(1.45)
Most of Fission Products (FP) are neutron-­‐rich nuclei, undergoing β -­‐ decay A
Z
!
239Pu
235U
X " Z +1A Y + e - + # e
Reactor monitoring with antineutrinos
235U
239Pu
Ef (MeV)
201.9
210.0
<Eν > (MeV)
1.46
1.32
<Nν>
(E>1.8MeV)
5.58
(1.92)
5.09
(1.45)
Most of Fission Products (FP) are neutron-­‐rich nuclei, undergoing β -­‐ decay A
Z
X " Z +1A Y + e - + # e
!
239Pu
235U
⇒  Power Reactors are copious an<neutrino emi>ers => neutrino physics = oscillation
parameter search: θ13, search for sterile neutrinos (« reactor anomaly »)
⇒  Use the discrepancy between an<neutrino flux and energies from U and Pu isotopes to infer reactor fuel isotopic composition => reactor monitoring, non-proliferation
and interest of the IAEA (see IAEA Report SG-EQGNRL-RP-0002 (2012). )
Reactor antineutrinos
2800 MWth
" 6 #e
200 MeV
" Standard nuclear power plant 900 MWe : " Usually detec<on through inverse-­‐β process on quasi-­‐free protons : !
!
~ 5 "10 20 # e /s
[C. Bemporad et al,. Rev. of Mod.
Phys., 74 (2002)}
" e + p # e+ + n
  ReacRon threshold : 1.8 MeV
  Cross secRon (α En2) : <σ> ~ 10-43cm2
2 x 511 keV
!
Prompt e+
E=1-8 MeV
νe
p
e+
n
Delayed n capture Gd nuclei Σγ ~ 8 MeV Gd
 Time correlation : τ ∼ 30µs
 Space correlation : < 1m
First Double Chooz, Daya-Bay and Reno results published in Phys. Rev. Lett. in 2012 !
Y. Abe et al Phys. Rev. Le>. 108, 131801, (2012) F. P. An et al., Phys. Rev. Le>. 108, 171803 (2012). J. K. Ahn et al., Phys. Rev. Le>. 108, 191802 (2012) ⇒  The Double Chooz experiment has devoted efforts to new computations of reactor
antineutrino spectra
⇒  Two methods were re-visited:
- One relying on the conversion of integral beta spectra of reference measured
by Schreckenbach et al. in the 1980’s at the ILL reactor (thermal fission of 235U, 239Pu and
241Pu integral beta spectra): use of nuclear data for realisRc beta branches, Z distribuRon of the branches… -­‐ The other being the summation method, summing all the contributions of the
fission products in a reactor core: only nuclear data : Fission Yields + Beta Decay properRes 6
*ArXiv : hep-exp/0606025
*http://doublechooz.in2p3.fr/Public/French/welcome.php
DOUBLE CHOOZ EXPERIMENT*
Mixing angle θ13 measurement (limit) + non-proliferation goal
ν flux
Normalization
@400m
ν
oscillation
@1050m
2 identical
8.3t targets
νe
νe,µ,τ
2 PWR-N4
2x4.27 GWth
1021 νe/s
  DC phase 1 (2011-14) : Far detector only, sin2(2θ13)<0.06 (1,5 years, 90% C.L.)
7
  DC phase 2 (2014-16) : Far + near sites, sin2(2θ13)<0.03 (3.5 years,90% C.L.)
Summation Method: Method based on individual
fission product beta decay summation
N (E" ) = $ Yn (Z, A,t ) # $ bn,i (E0i )Pv (Ev , E0i , Z )
fissile
mat. + FY
Core
neutron
geometry
!
flux
n
i
!
models
β-branch
β-spectra database :
Core Simulation
Evolution Code MURE
β- decay rates
Yi ( Z , A , t )
exp.
spectrum
TAGS, Rudstam et al.,
ENSDF, JEFF, JENDL, …
other evaluated nuclear databases
weighted Σ
β- /νe spectra
S" ,i ( Z , A , E" )
Total νe and β - energy spectra
!
with possible complete error treatment
+off-equilibrium effects The MURE* Code
  The MURE Code (MCNP U<lity for Reactor Evolu<on) :
-  C++ interface to the Monte Carlo code MCNP (static particle transport code)
-  Open source code available @ NEA: http://www.oecd-nea.org/tools/abstract/detail/nea-1845
-  Used for the 1st phase of the Double Chooz experiment
Static
computation
t=0
MCNP
+ evolution s
condition (power …)
Static
computation
t = Δt1
MCNP
+ evolution s
condition (power …)
Static
computation
t = Δtx
MCNP
Material evolu1on: Resolu1on of Bateman differen1al equa1ons decays
reactions induced by neutron
 Outputs provided: keff, neutron flux, inventory, reaction rates + adapted to compute
antineutrino spectra
  Development of a complete core simulation with a follow up of core operating parameters
  Can be used also for simple geometries: ILL spectra computation
From A. Onillon
9
Ingredients to build beta and antineutrino spectra
  Nβ (W) = K pW(W-W0)2 F(Z,W)L0(Z,W)C(Z,W)S(Z,W)Gβ (Z,W)(1+δWMW)
Where W=E/mec2, K = normaliza<on constant,
pW(W-W0)2 = phase space, to be modified if forbidden transi<ons F(Z,W) = Fermi func<on L0(Z,W) and C(Z,W) = finite dimension terms (electromagne<c and weak interac<ons) S(Z,W) = screening effect Gβ (Z,W) = radia<ve correc<ons δWM = weak magne<sm term The first results were published in Th.A. Mueller et al, Phys.Rev. C83(2011) 054615:   Summation method: Energy conserva<on for conversion into an<neutrino spectrum, for each beta branch of each fission product + realis<c Z distribu<on of the fission products 10
« Summation » Method with the MURE* code
*MCNP Utility for Reactor Evolution:
-  Computes the fission product distributions to
couple with beta decay nuclear databases
-  Computes off-equilibrium effects
-  Prediction of any antineutrino energy spectrum for
individual fissible nuclei or full reactor cores, for
neutrino physics or non proliferation
But Pandemonium effect:
Overestimate of the reference spectra @ high
energy + shape distortion
⇒  Requires new measurements of fission product
beta decay properties
11
*MCNP Utility for Reactor Evolution: http://www.nea.fr/
tools/abstract/detail/nea-1845.
Th. Mueller et al. Phys. Rev. C 83, 054615 (2011).,
C. Jones et al. Phys. Rev. D 86 (2012) 012001, arxiv.org/
abs/1109.5379
Newly Converted Spectra
Th.A. Mueller et al, Phys.Rev. C83(2011) 054615  Assume a 10% error on the summation method spectra for all the bins, based on the discrepancy with ILL spectra => no complete error estimate yet
 Assuming that summa<on method not yet precise enough, develop a mixed approach using
nuclear databases + fictive branches to reproduce the ILL spectra
Ratio of Prediction / Reference ILL data
ILL electron data anchor point
Fit of residual: five effec<ve branches are fi>ed to the remaining 10% ⇒  Suppresses error of full Summa<on Approach, if assump<on that ILL data = only reference 
Built with Nuclear Data
  “true” distribu<on of all known β-­‐ branches describes >90% of ILL e data ⇒  reduces sensi<vity to virtual branches approxima<ons Newly Converted Spectra
i ( fission .Mev-1 )
  Recent re-evaluations by
- Th.A. Mueller et al, Phys.Rev. C83(2011) 054615.
- P. Huber, Phys.Rev. C84 (2011) 024617
241Pu
1
-1
238U
239Pu
235U
10
10

-1
Off-equilibrium corrections included
(computed with MURE)
  Summation calculations, database
comparisons and fission product
distribution= new 238U prediction
-2
10-3
2
3
4
5
6
7
8
E i (MeV)
Recent works defining new reference on the neutrino flux prediction for
neutrino physics
Newly Converted spectra…
"   ILL data = unique and precise reference => converted ν spectra = +3% normaliza<on shij with respect to old ν spectra, similar results for all isotopes (235U, 239Pu, 241Pu) ⇒  Origin of the bias identified:
"   ILL conversion procedure (only virtual branches): 2 independent biases:   Low energy: correc<on to Fermi theory should be applied at branch level   High energy: mean Z fit is not accurate enough. ⇒  « Reactor anomaly »: all reactor neutrino experiments are below the predic<on (G. Men<on et al. Phys. Rev. D83, 073006 (2011)). ⇒  Now looking for sterile neutrinos as a poten<al explana<on to the reactor anomaly: Nucifer exp., + numerous projects: SOLiD (UK), STEREO (France), SCRAMM(US-­‐
Ca), Neutrino-­‐4 (Russia), DANSS(Russia), + Mega-­‐Curie sources in large ν detector… (white paper: K. N. Abazajian et al., h>p://arxiv.org/abs/1204.5379.) ⇒  Other explana<ons s<ll possible: large uncertainty for Weak Magne<sm term => could change normaliza<on of spectra, or normaliza<on of ILL data On the Nuclear Data side…
The reactor antineutrino estimate is not the only
one to suffer from the Pandemonium Effect:
Similar problem for Reactor Decay Heat (initiated
by Yoshida et al. see Nuclear Science NEA/WPEC-25
(2007), Vol. 25)
⇒  TAS experiments
TAS Technique
Pandemonium effect**:
Due to the use of Ge detectors to measure the decay schemes: lower efficiency at higher
energy
→ underestimate of β branches towards high energy excited states: overestimate of the high
energy part of the FP β spectra
Solution: Total Absorption Spectroscopy (TAS)
Big cristal, 4π => A TAS is a calorimeter !
Picture from A. Algora
** J.C.Hardy et al., Phys. Lett. B, 71, 307 (1977)
16
  12 BaF2 covering ~4π
  Detection efficiency of γ ray
cascade ~ 100%
  Si detector for β
TAGS developed by the Valencia team (Spain, B. Rubio, J.L. Tain, A. Algora et al.) : Proceedings
of the Int. Conf. For nuclear Data for Science and technology (ND2013)
TAS MEASUREMENTS @ JYVÄSKYLÄ UNIV. (JYFL)
  IFIC of Valencia (J.L. Tain et A. Algora et al.)
Reactor Decay Heat in 239Pu: Solving the γ Discrepancy in the 4–3000-s Cooling
Period,
Algora et al., Phys. Rev. Lett. 105, 202501 (2010),
D. Jordan, PhD thesis, Univ. Of Valencia 2010
⇒  Taking into consideration the TAS data of the 102;104–107Tc, 105Mo, and
measured @ Jyväskylä
⇒  i.e. correcting 5 nuclei out of 7 for the Pandemonium effect
101Nb
isotopes
Impact of the results for 239Pu:
electromagnetic component
Integral
measurement of
reference
Summation method
calculations of the
decay heat
17
D. Jordan, A. Algora et al. Phys. Rev. C 87, 044318 (2013)
New measurements @JYFL (Jyväskylä,Finland)
  7 nuclei have been already measured at JYFL of Jyväskylä (Finland), analysis is on-­‐going (A. Algora et al. Proc. of the Int. Conf. ND2013): 86Br, 87Br, 88Br, 91Rb, 92Rb, 93Rb, 94Rb   Mo<va<ons: Decay Heat, Reactor Antineutrinos, Nuclear Structure, Nuclear Astrophysics
  New Experiment @ JYFL in 2013: Reactor An<neutrino proposal (9 nuclei)   Perspectives @ ALTO and SPIRAL2
PhD Thesis work:
•  E. Valencia (IFIC-Valencia)
•  S. Rice (University of Surrey)
•  Z. Issoufou (SUBATECH-Nantes): see his Poster @ This Conference
JYFL: Good selec<on of the measured nucleus needed → IGISOL* + Penning trap JYFLTRAP** *J.Ärje et al., NIM A 247,431 (1986)
**V.S.Kolhinen et al., NIM A 528,776 (2004)
Valencia-­‐Surrey TAS 18
Back to the summation method for antineutrinos:
-­‐ the only one adapted to the computa<on of the an<neutrino emission associated to various reactor designs (roadmap for IAEA) ;
-­‐ computation of an<neutrino spectra for which no beta spectrum was measured ; -­‐ off-­‐equilibrium effects -­‐ different binnings etc… for reactor neutrino experiment analyses (DC, DB, …) -­‐ AND one of the only alternatives to ILL spectra !!! ⇒  Update of summation method spectra for 235U, 239Pu, 241Pu and 238U with the latest
published TAS data:
« New an<neutrino energy spectra predic<ons from the summa<on of beta decay branches of the fission products », Phys. Rev. Le>. 109, 202504 (2012), M. Fallot, S. Cormon, M. Es<enne, A. Algora, V.M. Bui, A. Cucoanes, M. Elnimr, L. Giot, D. Jordan, J. Mar<no, A. Onillon, A. Porta, G. Pronost, A. Remoto, J. L. Taìn, F. Yermia, and A.-­‐A. Zakari-­‐Issoufou et al., h>p://arxiv.org/abs/1208.3877 19
Summation method: ingredients
  Nβ (W) = K pW(W-W0)2 F(Z,W)L0(Z,W)C(Z,W)S(Z,W)Gβ (Z,W)(1+δWMW)
Where W=E/mec2, K = normaliza<on constant,
pW(W-W0)2 = phase space, to be modified if forbidden transi<ons F(Z,W) = Fermi func<on L0(Z,W) and C(Z,W) = finite dimension terms (electromagne<c and weak interac<ons) S(Z,W) = screening effect Gβ (Z,W) = radia<ve correc<ons δWM = weak magne<sm term (the most uncertain one ! Cf. P. Huber, could change the
normalization of the spectra if very different value…)
  Using Huber’s prescrip<ons (formulae and values from PRC84,024617(2011)) + energy conserva<on for conversion into an<neutrino spectrum, for each beta branch of each fission product   Individual fission yields from the JEFF3.1 database are used 20
Summation method: ingredients
  In order to choose one specific nuclear decay database for one given nucleus, the order in which the bases are read is important: the first one in which the fission product is found is the chosen one: The Greenwood TAS data set (29 nuclei), the experimental data measured by Tengblad et al. (85 nuclei), experimental data from the evaluated nuclear databases: JEFF3.1 (305, 345, 347, and 318 nuclei, respecRvely, for 235U, 239Pu, 241Pu, and 238U) and JENDL2000 (61, 62, 61, and 58 nuclei, respecRvely), Evaluated Nuclear Structure Data File nuclei (94, 106, 109, and 97 nuclei respecRvely), Gross theory spectra from JENDL (214, 215, 227, and 221 nuclei, respecRvely), and the ‘‘Qβ’’ approxima<on for the remaining unknown nuclei (22, 32, 38, and 33 nuclei, respecRvely). ⇒  810, 874, 896 and 841 fission products taken into account respec<vely   Irradia<on <mes with MURE: 12 h for 235U, 1.5 days for 239;241Pu, and 450 days for 238U. ⇒  Taking into considera<on the latest published TAS data of the 102;104–107Tc, 105Mo, and 101Nb isotopes (A. Algora et al. Phys. Rev. Le>. 105, 202501 (2010)) ? ⇒  i.e. correc<ng 5 nuclei out of 7 for the Pandemonium effect 21
Inclusion of the latest TAS data in the Antineutrino Summation
Spectra:
Phys. Rev. Le>. 109, 202504 (2012)
Ratios of summation antineutrino
spectra including the new TAS data for
102;104–107Tc, 105Mo, and 101Nb over the
same spectra but with the JEFF3.1
data
22

energy spectra: no<ceable devia<on from unity observed in the 0–
6 MeV energy range reaching an 8% decrease. 
energy spectrum: effect reaches a value of 3.5% at 2.5–3 MeV. 
1.5% at 2.5–3.5 MeV, expected since these nuclei are a small contribu<on to the 235U spectrum. 239;241Pu
238U
235U:
Inclusion of the latest TAS data in the Antineutrino Summation
Spectra:
Phys. Rev. Le>. 109, 202504 (2012)
Ratios of summation antineutrino
spectra including the new TAS data for
102;104–107Tc, 105Mo, and 101Nb over the
same spectra but with the JEFF3.1
data

energy spectra: no<ceable devia<on from unity observed in the 0–
6 MeV energy range reaching an 8% decrease. 
energy spectrum: effect reaches a value of 3.5% at 2.5–3 MeV. 
1.5% at 2.5–3.5 MeV, expected since these nuclei are a small contribu<on to the 235U spectrum. 239;241Pu
238U
235U:
⇒  Shows the important role of the Pandemonium nuclei in the ν summa<on spectra ⇒  The summation spectra are among the only ways to estimate the antineutrino spectra
independently from the still unique ILL integral β-spectra
23
⇒  New measurements required, list of nuclei iden<fied On the Particle Physics side…
Sterile Neutrino hints ?
"
Reactor Anomaly:
  converted ν spectra = ˜+3% normaliza<on shij with respect to old ν spectra, similar results for all isotopes (235U, 239Pu, 241Pu)   Neutron life-­‐<me 2 flavour simple scheme :   Off-­‐equilibrium effects POsc= sin22θ sin2(1.27Δm2[eV2]L[m]/E[MeV]) G. Men<on et al. Phys. Rev. D83, 073006 (2011) 25
=> Light sterile neutrino state ? could explain L=10-­‐100m anomalies, Δm2 ≈ 1 eV2 • candidate can’t interact via weak interac<on : constrained by LEP result on 3 families => so can only exist in sterile form Sterile Neutrino hints ?
"
Reactor Anomaly:
  converted ν spectra = ˜+3% normaliza<on shij with respect to old ν spectra, similar results for all isotopes (235U, 239Pu, 241Pu)   Neutron life-­‐<me   Off-­‐equilibrium effects sterile neutrino with Δm2 ≈ 1 eV2 can account for rate reduc<on at L ≈ 10 − 100 m "   Gallium Anomaly: radioactive sources in gallium solar neutrino exps.: νe +71Ga =>
71Ge + e−, see also a deficit of the awaited antineutrino flux, oscilla<ons with Δm2 ≈ 1 eV2 can lead to reduc<on of the νe flux within the detector volume "   LSND and then MiniBooNE experiments report excess in appearance (an<-­‐) νe spectra, which can be consistently interpreted in terms of oscilla<on, but remain in tension with disappearance experiments 26
Some Proposals for Sterile Neutrino Search…
Searches for νe disappearance: " reactor experiments (Nucifer, SCRAAM, Neutrino-4, SOLid, STEREO, DANSS,
Poseidon...): very short baseline needed, small reactors, shape analysis
" radio-active source experiments in/next to large detectors: Ce-LAND
(KamLAND), Borexino, SNO+, DayaBay,...
Accelerator based searches for eV-­‐scale oscilla<ons " MiniBooNE extensions (e.g., MicroBooNE), LANL LAr
" LAr-TPC/muon spectrometer at CERN SPS
" Stored muon beam (nuSTORM)
Other experiments… See “Light Sterile Neutrinos: A White Paper” Abazajian et al., 1204.5379 And the recent Global Analysis by J. Kopp, P. A.N. Machado, M. Maltoni, T. Schwetz arXiv:1303.3011 + T. Schwetz’s talk @ APC, 2013 27
Experiments @ Reactors
SCRAAM
Site: 24m baseline, 3.4GW reactor SONGS (US) and
12m baseline 150MW reactor ATR (US)
Detector: 1.5t fiducial, active+passive shielding
Challenges: 40% efficiency, Eres = 10%/√E, S/B~8
Timescale: 2012-2016
Neutrino4
Site: baseline 6m-12m, 100MW reactor SM3
(Russia)
Detector: 24 segments 1.4*1*1m3 or 5 sections
movable of Gd-LS
Rates: 2500 nu-s/day for 1t @ 6m
Timescale: 2013 – tests @ WWR-M (18MW)
28
DANSS
Site: baseline 9.7-12.2m on moving platform,
3GW reactor KNPP (Russia)
Detector: 1m3 of highly segmented Gd-PS
Features: 9000nu/day
Status: 2013 – deployment, prototype DANSSino just
took 80 days of data, including 2 reactor OFF periods
Nucifer@OSIRIS
First run in 2012 indicated an unexpected
background from primary loop circuit
6 MeV γ σ
  70 MW Research Reactor, enriched 235U
fuel (20%), very compact (61x61x63 cm3)
  Nucifer 7 m from the core
  10 mwe overburden
  Huge gamma and neutron background
from research reactor
New shield
10 cm of lead
(march 2013)
29
Nucifer@OSIRIS
First run in 2012 indicated an unexpected
background from primary loop circuit
6 MeV γ σ
  70 MW Research Reactor, enriched 235U
fuel (20%), very compact (61x61x63 cm3)
  Nucifer 7 m from the core
  10 mwe overburden
  Huge gamma and neutron background
from research reactor
New shield
First antineutrino signal seen@7σ with 2 weeks data
10 cm of⇒
lead
⇒  Need an extra shielding to decrease accidental rate:
(march 2013)
intallation for fall 2013
⇒  Sterile neutrino hint possible after upgrade
30
Proposals in France: STEREO
Proposed by D. Lhuillier (CEA)
Site: ILL, France Schedule: 2014-2015
Threshold: 2MeV running 300d S/B = 1.5 L = 8m Segmented target: 5*40cm cells → 2m3 Gd-­‐doped liquid scin<llator Ac<ve Veto + Gamma Catcher: 2m3 Acrylic buffer for uniform response Shielding: against cosmogenics (Čk water tank + PMT) front wall (beam shu>er, against n & gamma) Lead + polyethylene (70t) surrounding target 31
750 nu/d expected Eff = 66% for neutron cut at 5 MeV (52%@6MeV) Eres ~15%@1MeV Shape-only analysis
Proposals in France: SoLid
Proposed by A. Vacheret (Oxford)
Site: ILL, France Schedule: 2014-2015
• Powerful discrimina<on between neutron and fast signals (EM) Trigger on neutrons (71% efficiency, patent MARS tech.) ⇒  Less shielding (no Lead), 20cm polyethylen ⇒  + Event Topology with Segmenta<on ⇒  Improved background rejec<on Detector element : EJ-­‐200 PVT cubes 5 cm x 5 cm x 5 cm + 6LiF:ZnS(Ag) screens 5 cm x 5cm x 250um Baseline : 6.75 m and 7.25 m 2x 1.44Ton detector mass • ~40% detec<on efficiency ajer coinc. + cuts • energy resolu<on : 0.22 at 1 MeV • S/B ~3:1 • Threshold 600keV 32
SOLid is a new type
of neutron detector,
based on well know
technology
=> Synergy with
SPIRAL2 ?
Prototype under
construction
Shape-only analysis
Conclusions & outlooks
  The ILL data are s<ll the only and most precise measurements, considered as a reference in neutrino physics   Newly converted ν spectra => normalization shift w.r.t previous ν spectra => « reactor
anomaly »
  A possible alternative = spectra built with the summa<on method   Pandemonium nuclei play a major role in the estimate of the antineutrino spectra using
the summation method and TAS measurements of these nuclei could allow us to
improve drastically the predictiveness of these spectra.
  Independent evaluations of the reactor spectra could provide new constraints on
the existence of light sterile neutrinos.
  Nuclear Physics: TAS experiment perspec<ves @ ALTO and SPIRAL2   Sterile Neutrino Search @ Reactors: STEREO and SoLid proposals, synergy with neutron detectors for Nuclear Physics   Interest for safeguards: ESARDA WG + IAEA ; Interest for Nuclear Data: WPEC 25
nuclear data meeting at IAEA in 2009, participation to the new IAEA CRP on beta-n emitters
33
THANK YOU
A List of Proposals
, soLid
« Sterile Neutrino Fits to Short-Baseline Neutrino Oscillation Measurements »
J. M. Conrad, C. M. Ignarra, G. Karagiorgi, M. H. Shaevitz, and J. Spitz
Advances in High Energy Physics Volume 2013, Article ID 163897
http://dx.doi.org/10.1155/2013/163897
35
Inclusion of the latest TAS data:
  With the recently measured TAS data set by Algora et al. Phys. Rev. Le>. 105, 202501 (2010):
« New an<neutrino energy spectra predic<ons from the summa<on of beta decay branches of the fission products », Phys. Rev. Le>. 109, 202504 (2012), M. Fallot, S. Cormon, M. Es<enne et al. Reconstructed an<neutrino energy spectra, including the latest TAS data from Algora et al. In the insets: ra<os of the spectra to the ones computed by Huber PRC84,024617(2011). 36
Neutrino oscillations
The Pontecorvo-Maki-Nakagawa-Sakata (PMNS) matrix
$ " e ' $1
0
& ) &
&" µ ) = &0 c23
& ) &
%" # ( %0 *s23
0 '$ c13
)&
s23 )& 0
)
c23 (&% *s13e i+
θatm
0
1
0
θ13, δ
s13e* i+ '$ c12
)&
0 )& *s12
&
c13 )(% 0
θsol
where cij = cos(θij), sij = sin(θij), δCP = Dirac phase, related to
CP violation (?)
!
s12
c12
0
0'$ "1 '
)& )
0)&" 2 )
)& )
1(%" 3 (
if ν=ν two more phases appear without
influencing oscillations
2 flavour simple scheme : POsc= sin22θ sin2(1.27Δm2[eV2]L[m]/E[MeV])
"   [Δm221 - θ12]
–
[Δm232 - θ23]
– sign(Δm232) - θ13 - δ
Solar ν
+
KamLAND
+
reactor @180 km
Atmospheric ν
+
K2K
+
MINOS & Superbeams
MSW-LMA
-5 eV2
12~7.6 10
sin2(2θ12)~0.8
(large angle)
Δm232~2.5 10-3 eV2
sin2(2θ23)~1
(max. angle ?)
Δm2
Superbeams
+
reactors @1-2 km
+
ν factory β beams
sin2(2θ13)<0.14 (CHOOZ)  θ13 !!!!
2011-2012 Double Chooz, Daya Bay, Reno
Mass hierarchy  sign(Δm232 ) ?
CP violation  δ phase ?
(meas. of Pα→β ≠ Pα→β)
Oscillations des neutrinos de réacteurs
P(νe → νe) = 1 – sin2(2θ13) sin2(Δm231L/4E) – cos4θ13 sin22θ12 sin2(Δm221L/4E)‫‏‬
φ1
φ2
Δm231 ~ Δm232
Chooz:
E 3 MeV
~
~ 310− 3 eV 2
L 1Km
Kamland:
E 3MeV
~
~ 210− 5 eV 2
L 175 Km
38
Bugey
ILL
Chooz
Palo Verde
Kamland
38
39
Double Chooz Predicted Neutrino Rate (1)
  Expected detected neutrino rate: With the mean energy released per fission : Inverse beta-­‐decay cross secRon Includes latest neutron life Rme: 40
  Recent re-­‐evaluaRons by -­‐ Th.A Mueller et al, Phys.Rev. C83 (2011) 054615 -­‐ P. Huber, Phys.Rev. C84 (2011) 024617   Off-­‐equilibrium correcRons included (from Th. Mueller et al. @ 100days) Reference anRneutrino spectra converted from the ILL data UPDATE
DChooz: Antineutrino flux and spectrum prediction
-  Far detector data only
-  No-Oscillation ⇒ reactor flux prediction via core simulations
-  Normalisation to the Bugey-4 cross-section with far detector
only
⇒ Reduced reactor systematics:
Full core simulations with the MURE code, with a
follow-up of thermal power and boron
concentration (>700h CPU for a complete cycle)
Numerical computation of the systematic error associated
to the fission rates with MURE over the fuel cycle
⇒  Fractions of fissions per isotope 235U=49.6%,
239Pu=35.1%, 241Pu=6.6%, and 238U=8.7% and the
fission rate covariance matrix.
⇒  Resulting relative uncertainties on the above fission
fractions are ±3.3%, ±4%, ±11.0% and ±6.5%
41
Total reactor error: 1.7%
Accurate reactor simulations keep the contribution of fission fraction uncertainties low
UPDATE
DOUBLE CHOOZ:
Rate + Shape Analysis:
sin2(2θ13) = 0.109±0.030(stat)±0.025(syst)
Impact in θ13 knowledge by DC
Combined effect: sin2(2θ13)>0 @ 99.9%C.L.
Y. Abe et al Phys. Rev. Lett. 108, 131801,
(2012)
Y. Abe et al. Physical Review D 86, 052008,
(2012)
42
Recent reactor experiments results
 Recent result publica<ons of reactor experiments: Double Chooz, Daya-­‐Bay (China) / Reno (Korea) Ndet
Vdet
Reactors
DC
2
8.3
2*4.25 GWth
Daya-Bay
6
20
6*2.9 GWth
Reno
2
16
6*2.8GWth
Y. Abe et al Phys. Rev. Lett. 108, 131801, (2012)
Y. Abe et al. Physical Review D 86, 052008, (2012)
F. P. An et al., Phys. Rev. Lett. 108, 171803 (2012).
J. K. Ahn et al., Phys. Rev. Lett. 108, 191802 (2012).
  The near detector measurements will allow detailed comparisons with the reactor
spectrum simulations  constraints on the antineutrino spectrum shape + non-proliferation
⇒  Measurements of the relative neutrino rate along the burnup @ 1% every month for
instance in DC near: comparison with the detailed Chooz core simulations
Ce-LAND
Nu sources in detectors
Borexino
Detect oscillations
through distortions
with baselines
A priori starting
from 2015-…
Daya Bay
SAGE 2
44
LENS
sterile
SNO+
Nu-beams
LAr CERN-SPS
Decay in Flight beam
Cern
2 LAr det.
Icarus-Nessie Proposal (L/E≈ km/
GeV => eV-scale 4th ν)
2017 ?
MicroBooNE
BNB FNAL
170t LAr TPC
2014-2017
LANL-Lar
5t Liq Ar
BNB FNAL
2015 deployment
45
Nucifer Sensitivity to Sterile Neutrinos
After upgrades, end 2013
46
arXiv:1303.3011v2 [hep-ph]
« An explanation of all hints in terms of oscillations suffers from severe tension
between appearance and disappearance data. The best compatibility is obtained in the
1+3+1 scheme with a p-value of 0.2% and exceedingly worse compatibilities in the 3+1
and 3+2 schemes. »
Global Analysis by J. Kopp, P. A.N. Machado, M. Maltoni, T. Schwetz arXiv:1303.3011 See T. Schwetz’s talk @ APC, 2013
47
48
From A.P. Serebrov (Neutrino-4)
49
50
Antineutrino Detection for Reactor Monitoring
  First mee<ng @ IAEA in 2003, with neutrino physics experts   2008 : Expert mee<ng @IAEA (physicists & inspectors) : IAEA Report « Final Report of the Focused Workshop on An<neutrino Detec<on for Safeguards Applica<ons », STR-­‐361, Feb. 2009.   2010 : Symposium on Interna<onal Safeguards: Preparing for Future Verifica<on Challenges: Creation of an ad-hoc WG
  1st IAEA Ad-Hoc WG meeting in Sept. 2011, IAEA Report “Proceedings of the first mee<ng of the Ad Hoc Working Group on Safeguards Applica<ons u<lizing An<neutrino Detec<on and Monitoring”, SG-­‐EQ-­‐GNRL-­‐RP-­‐0002 2012.   Crea<on of a sub-WG devoted to antineutrino detection of the Novel technologies WG of
the European Safeguards Research and Development Association (ESARDA) (
http://esarda2.jrc.it/internal_activities/WG-NT-NA/index.html)  Next ESARDA WG meeting: 35rd ESARDA meeting: May 2013, Belgium Key words:
an<neutrino detec<on, R&D, compact detectors, PSD, actual and future reactors, simula<ons, prolifera<on scenarios, NUCLEAR DATA …  Projects of design of small antineutrino detectors dedicated to reactor
monitoring: US (SONGS, …), Japan (Tohoku, Tokyo), Russia (DANSS), Brazil (ANGRA), Italy (CORMORAD), France (Nucifer), GB (MARS/SOLiD), … Observable: beta feeding => beta strength
An ideal TAS would give
directly the β-intensity Iβ
which is linked with the βstrength Sβ:
Ii
Si =
f (Qβ − Ei )T1 2
Statement of the problem:
Ii =
Rela<on between TAS data and the β-­‐
intensity distribu<on: d i = ∑ Rij f j
j
Deconvolution (Inverse
problem) algorithms
52
[s ]
−1
fi
∑f
k
k
j −1
•  Spectrum must be clean k =0
•  Response must be accurately known R j = ∑ b jk g jk ⊗ R k
Monte Carlo
simulations
+
Nuclear statistical
model
•  Solu<on of inverse problem must be stable NIM A430 (1999) 333 NIM A571 (2007) 719
NIM A430 (1999) 488 NIM A571 (2007) 728
Off-equilibrium effects
MURE code: core composition and off-equilibrium effects
Relative change of ν spectrum w.r.t
infinite irradiation time
Relative Off-equilibrium Effect:
close to beta-inverse threshold, a
significant fraction of the ν
spectrum takes weeks to reach
equilibrium
⇒  Sizeable correction of ILL data in
the low E range.
Weak magnetism
From P. Huber’s PRC Experimental slope in good
agreement for transitions
with low ft values
Contribution of large ft’s in
fission neutrino spectra ?
⇒  Yes: high log(ft) values have a sizeable contribution to fission ν spectra across all E
range (reflects the large contribution of forbidden decays)
⇒  No obvious argument can reject a substantially larger WM contribution or error
55
Extracted from M.Estienne’s ND2013 proceedings
56