1 n_TOF data-analysis workshop CERN, Geneva, 25-27 February 2015 Roberto Capote, IAEA Nuclear Data...

1 n_TOF data-analysis workshop CERN, Geneva, 25-27 February 2015

Roberto Capote, IAEA Nuclear Data [email protected] www-nds.iaea.org

NUCLEAR DATA EVALUATION NEEDS: Impact of n_TOF measurements on nuclear applications

Roberto Capote and Naohiko Otsuka

Nuclear Data Section

International Atomic Energy Agency



OUTLINE

Nuclear data evaluation in a nutshell

Overview of n_TOF results and their impact

Summary and outlook



Nuclear Data Evaluation

From D. Neudecker, S. Gundacker, H. Leeb et al., ND2010, Jeju Isl., Korea



Definition of (ND) EvaluationA properly weighted combination (usually by GLSQ fit) of selected experimental data (and nuclear reaction modelling results).

Bayesian approaches: “Non-model” GLSQ fit: neutron standards (STD) IAEA STDs: https://www-nds.iaea.org/standards/ R-matrix (non-model fit) – RR evaluations Model prior + GLSQ fit Experimental nuclear physicists Theoreticians and reaction modellers Evaluators

https://www-nds.iaea.org/standards/





Neutron standards:

Files include additional energy range beyond STD !!

ENDF/B-VII.1 almost = STD

JEFF-3.2 IAEA STD

JENDL-4.0 IAEA STD

www-nds.iaea.org/standards/

Nuclear Data Sheets 110 (2009) 3215-3324





Evaluated 238U(n,f) vs. IAEA STD cross section



Evaluated 238U(n,f) vs. IAEA STD cross section

raw EXFOR ratio data U8/U5, U5 std



Nuclear reaction data evaluation

Resonance energy range ( << D)

Fast neutron range ( >> D stat models) keV for actinide, MeV for Ni, Fe, Cr,…

Unresolved resonance range (in between) (self-shielding)



Evaluation – resonance range (RR)

Theoretical predictions not possible yet Resonance parameters must be obtained

from fitting ALL AVAILABLE experimental data Modern resonance fitting codes produce “best fit”

parameters as well as their covariances(e.g. SAMMY, REFIT, CONRAD, etc.)



Evaluation – resonance range - example



Depends on resolution functionRPs, background, …To be combined with transmission ...



n_TOF data in EXFOR

&

impact on applications



A very optimistic point of view…

Data published & at EXFORextracted from Lederer’s pres.



What do engineers need?

)1()21()2()2()2()2(

)2()12()()()()1()1()1()1(1

a

gggfga

D

kD

I need cross sections …

Usually evaluated cross sections from ENDF-B,JEFF,JENDL,…

Back to the real world



What n_TOF collaboration usually provided?

Here you are …It is all described inmy article in the Phys.Rev. C !

Or even worse …Please use my Resonance Parameters

Impossible to evaluate data in the RR !!!



n_TOF Published Fission Data in EXFOR (www-nds.iaea.org/nrdc/n_tof)

Target 1st author Reference EXFOR RP <σ> σ* Y

Pbnat D. Tarrio PRC83(2011)044620 23151 5,8,X --

209Bi 5,8,X --

233U M. Calviani PRC80(2009)044604 14257 X X

F. Belloni EPJA47(2011)2 23128 5,X

234U C. Paradela PRC82(2010)034601 23126 X X

D. Karadimos PRC89(2014)044606 23231

236U R. Sarmento PRC84(2011)044618 23131 X X

237Np C. Paradela PRC82(2010)034601 23126 X 5,X

241Am F. Belloni EPJA49(2013)2 23148 5,X

243Am F. Belloni EPJA47(2011)160 23148 5,X

245Cm M. Calviani PRC85(2012)034616 23168 X

U5/U8 C. Paradela PRC91(2015)024602 in comp. X --

* 5: ratio to 235U(n,f) cross section; 8: ratio to 238U(n,f) cross section



P.M. Milazzo et al, AIP 1265 (2010) 477

How evaluators can improve evaluations with no data?

233U(n,f)



n_TOF Published Capture Data in EXFOR (1/4)(http://www-nds.iaea.org/nrdc/n_tof)

# Target 1st author Reference EXFOR RP MACS <σ> σ Y

1 24Mg C. Massimi PRC85(2012)044615 23163 X X

2 25Mg X X3 26Mg X X4 58Ni P. Žugec PRC89(2014)014605 23210 X X X X5 62Ni C. Lederer PRC89(2014)025810 23195 X X6 63Ni X X X7 90Zr G. Tagliente PRC77(2008)035802 22978 X X

8 PRC87(2013)014622 23194 X9 91Zr PRC78(2008)045804 23044 X X

10 PRC87(2013)014622 23194 X11 92Zr PRC81(2010)055801 23117 X X12 PRC87(2013)014622 23194 X

MACS – astrophysics, Yield (Y) – nuclear energy

http://www-nds.iaea.org/nrdc/n_tof





13 93Zr G. Tagliente PRC87(2013)014622 23194 X X

14 94Zr PRC84(2011)015801 22978 X X15 PRC87(2013)014622 23194 X16 96Zr PRC84(2011)055802 22978 X X17 PRC87(2013)014622 23194 X18 139La R. Terlizzi PRC75(2007)035807 22930 X X19 151Sm S. Marrone PRC73(2006)034604 22893 X X X

20 186Os M. Mosconi PRC82(2010)015802 22796 X X21 K. Fujii PRC82(2010)015804 23027 X22 187Os M. Mosconi PRC82(2010)015802 22796 X X23 K. Fujii PRC82(2010)015804 23027 X24 139La R. Terlizzi PRC75(2007)035807 22930 X X







25 188Os M. Mosconi PRC82(2010)015802 22796 X X

26 K. Fujii PRC82(2010)015804 23027 X27 197Au C. Massimi PRC81(2010)044616 23067 X28 C. Lederer PRC83(2011)034608 23152 X X X29 204Pb C. Domingo- PRC75(2007)015806 22945 X X X30 206Pb PRC76(2007)045805 22984 X X31 207Pb PRC74(2006)055802 22946 X X

32 209Bi PRC74(2006)025807 22944 X X33 232Th G. Aerts PRC73(2006)054610 22931 X *34 F. Gunsing PRC85(2012)064601 23167 X35 237Np C. Guerrero PRC85(2012)044616 23069 X X36 241Am K. Fraval PRC89(2014)044609 23237 X







37 243Am E. Mendoza PRC90(2014)034608 23254* X X X X


* in compilation

Suggestions: No need to compile into EXFOR by n_TOF ! No need to centralize submission (data lost?) First author should submit (as approved by PC):

1) the paper (to the journal)2) the yield and other data to the IAEA




https://www-nds.iaea.org/exfor/x4send.htm How to submit the data to the IAEA?

Complicated??

https://www-nds.iaea.org/exfor/x4send.htm



TAKE HOME MESSAGE

Job is not finished till ALL data are submittedRecommendation: submit the yield to the IAEA with the paper to the journalBoth for capture and fission experiments:

Capture/Fission yields (= input for SAMMY) Cross sections (preferably what is measured = ratio to STD)Only exception: (n,f) or (ng) data above the Resonance Range (in this case only cross sections are needed)

n_TOF impact on (n,g) evaluations low (02/15)Only 232Th(n,g) capture yield used in IAEA (other) evaluation so far (adopted by..) !!!Situation is improving (2 new sets) but huge backlog needs to be sorted out

n_TOF provided excellent data on U5f/U8f to the IAEA STD group Ratios of other STD cross sections needed – e.g. Au(n,g)/U8(n,g),Li6t/10Ba

1 n_TOF data-analysis workshop CERN, Geneva, 25-27 February 2015 Roberto Capote, IAEA Nuclear Data...

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