CCFE is the fusion research arm of the United Kingdom Atomic Energy Authority

EAF-2010 – the best of a generation

Jean-Christophe Sublet, Lee Packer Euratom/CCFE Fusion Association

Culham Science Centre

and

Jura KopeckyJUKO Research

Overview of presentation

• Summary of modifications made from EAF-2007 release to EAF-2010

• Modifications to SAFEPAQ Cross Section Analysis Tool in support of SACS– Automatic generation of cross section data for

threshold reactions• Distinguishing threshold reactions• Plotting the skewness parameter of cross sections

for threshold reaction types

• Conclusions and the future

Main comments on EAF-2010• EAF-2010 is now

completed

• EAF-2010 will be the last of the generation of EAF files.

• It will be the most complete and improved version of the EAF files – the best of the generation

Activities: EAF-2007 to EAF-2010• Revision of all reaction channels supported by experimental

data using– visual comparison with EXFOR and updated Private EXFOR

(most recent data not yet included in EXFOR) databases – SACS analysis– C/E analysis at reference energies (0.0253 eV, 30 keV, 14.5 MeV

and RIs)

• Update and revision of capture data:– Extensive reviewing of all capture cross sections including the

revision of applied XS systematic (in particular 30 keV)– Results are in detail presented in:

RA Forrest, J Kopecky and AJ Koning, Revisions and improvements of neutron capture cross sections for EAF-2010 and validation of TALYS calculations, UKAEA 546, March 2008.

– Associated uncertainty data based on TALYS

Activities: EAF-2007 to EAF-2010 threshold reaction data

• Update and revision of threshold reaction data:– Revision of (n,d) and (n,n’p) XS to improve the agreement

with activation experiments for (n,d + n,n’p) cross sections– Revision of neutron emission channels (n,2n) and (n,3n) to

compensate for competition with (n,f)– Revision of XS based on the validation using integral

measurements. Reported in: RA Forrest et al., Validation of EASY-2007 using integral measurement, UKAEA 547, April 2008.

– J-Ch. Sublet et al., Decay power: a comprehensive experimental validation.

Activities: EAF-2007 to EAF-2010 uncertainties

• Update and revision of uncertainty file (a major action in this work):– Build from TENDl-2009 variance files– Revision of non-threshold (Score = 0) reactions: new error

factors introduced from XS systematics– Revision of non-threshold (Score > 0) reactions based on

comparison with experimental information– Revision of all non-threshold reactions: new semi-quantitative

approach used for error factors of 1/v and <100 keV regions, based on error propagation of (0.0253 eV) and RI with corresponding C/E values.

Activities: EAF-2007 to EAF-2010 Status - Assembling

• Assembling the EAF-2010 starter file– the starter file in a point-wise format has been

assembled using the EAF-2007 list of targets (816)– The action of modifications has been documented in

EAF-Doc-50, Revision and modifications for EAF-2010, by J. Kopecky (July 2009).

– Correctness of formats for group structure processing by SAFEPAQ-II has been tested.

– Addition a two new groups structure Red-616 and LANL-66

Activities: EAF-2007 to EAF-2010 Validation

• Validation of the EAF-2010:– A complete validation against all available differential measurements

• By SACS analysis of all major reactions with Q < 20 MeV • By C/E histogram analysis at major pertinent energies 0.0253 eV,

30 keV (n,g), 14.5 MeV and resonance integrals • The results are presented in EAF-Doc-51, Validation of EAF-2010,

by J. Kopecky (November 2009).

– A complete validation against all available integral measurements experiments (FNS, FNG, REZ, etc…)

– The validation reports will be produced with emphasis on different nuclear applications (High energy, inertial and tokamak fusion, reactor types).

• Reactions that tend to be most important for fusion applications are:

– (n,2n) – neutron multiplication

– (n,p) - produces hydrogen– (n,) - produces helium– (n,)– (n,n') – for isomeric states– However, other reaction

types can be important

data for 86 reaction types

Neutron-induced reactions

Statistical Analysis of Cross Sections (SACS)

•See, R A Forrest et al., Detailed analysis of (n,p) and (n,) cross sections in the EAF-2007 and TALYS generated libraries, Fus. Eng. Des. 2008.

Analysis options: Distinguish Threshold Reactions

Defining skewness for threshold reactions

LR

LRk

Skewness parameter,

SACS: Skewness parameter implementation

Statistical analysis of cross sections plots

• Extract (store) polynomial fit coefficients to each set of cross section statistical parameters (versus asymmetry) for a given reaction type.

EAF-2010 example of SACS

• The following questions needs some attention:– The competition of proton emission with the neutron channel, which is

manifested in (n,2n) vs (n,n’p), (n,p) and at higher energies (n,2p) depending on the binding energies of neutrons and protons. This influences the width and skewness of excitation curves for the above reaction channels. See examples for (n,p).

– This is the reason effort was given in the extension of SACS analysis.

Cross section parameters

Generate cross section data tool

Fitting options

Calculatedquantities

Generate cross section data tool: 7 reaction types enabled

Fitting options

•P3 – 3rd order polynomial, •P4 – 4th order polynomial•Exp – exponential fit•Parenthesis refers to points which the curve passes through

Error handling: all required trendlines are not stored

Error handling: all required trendlines are not stored

Error handling: user selects non-threshold reaction type for the selected target

Cubic fit to Eth, Elow and Emax

bAx

xbA-1 • Determine A-1 using Gauss-Jordan elimination method

and multiply by b matrix solution to cubic coefficients.

0

2

0

a

a

a

a

01E2E3

1EEE

1EEE

1EEE

max

max

4

3

2

1

max2max

max2max

3max

low2low

3low

th2th

3th

432

23

1 aEaEaEaE

Fits well over asymmetry range 0.01 – 0.25

Option 1: Quartic fit to Emax, Ehigh and E30; exponential fit to 30 and 60 MeV

3011Ea1110

30

max

max

9

8

7

6

5

30230

330

max2max

3max

30230

330

430

high2high

3high

4high

max2max

3max

4max

eaa

0

2

a

a

a

a

a

01E2E3E4

01E2E3E4

1EEEE

1EEEE

1EEEE

982

73

64

5 aEaEaEaEaE

Ea10

11eaE

Option 2: Cubic fit to Emax and Ehigh; exponential fit to Ehigh and 60 MeV

high10Ea109

max

8

7

6

5

high2high

max2max

high2high

3high

max2max

3max

eaa

0

2

0

a

a

a

a

01E2E3

01E2E3

1EEE

1EEE

Ea9

10eaE

872

63

5 aEaEaEaE

Options 4 and 5: Lorentzian fit to parameters

• Standard Lorentzian:

• Modified Lorentzian:Energy

0 10 20 30 40 50 60

0

1

2

3

4

5

Energy

0 10 20 30 40 50 60

0

1

2

3

4

5

6

7

32

2max

t1

aEaEE

EEaE

2

2

max

1

a

EE1

aE

Options 4 and 5: Modified Lorentzian

• Solve for a1, a2 and a3 using 3 conditions.

• Cannot directly use the Gauss-Jordan method of matrix inversion used previously, so solve this problem algebraically.

• Three unknowns require three conditions:

– Option 4: passing through Eh, Emax and d/dE=0 at Emax

– Option 5: passing through El, Emax and Eh

32

2max

t1

aEaEE

EEaE

Small improvements: omit systematic error bars

Concluding remarks for SAFEPAQ

• SAFEPAQ is a tool which can be used to plot and compare evaluations from all sources.

• It is continuously being improved: several new features have been added to enhance the plotting functionality and some tools to aid the evaluator(s)

• SAFEPAQ will continue to be used as an integral part of the evaluation process - future development of the tool will focus on tools to aid the merge of transport and activation data.

(n,p) for Final

Max

cro

ss s

ectio

n (b

)

Asymmetry (s)

1E-03

1E+01

1E-02

1E-01

1E+00

0.00 0.05 0.10 0.15 0.20 0.25

Integral C/E for Fe-54(n,p)Mn-54

C/E

Neutron Spectrum

C/E = 0.9504

C/E = 1.0436

C/E = 0.9722

C/E = 1.0833

C/E = 0.9669C/E = 0.9422

C/E = 1.0302

C/E = 0.9926C/E = 0.9949

C/E = 1.1032C/E = 1.1150

C/E = 1.1645

C/E = 0.9806

C/E = 1.0208

C/E = 1.0569

C/E = 1.2776

1.10

0.91

0.70

0.90

1.10

1.30

1.50

sneg_2 fng_f82h.asc cf252_flux_1 cf252_flux_1 cf252_flux_1 fzk_ss316 fng_vanad.asc rez_DF

sneg_1 fzk_2 fns_7hour cf252_flux_1 cf252_flux_1 fzk_ss316 fzk_1 fng_eurofer.asc

Y-89(n,2n)Y-88

Final

Cro

ss s

ection (

b)

Energy (eV)

0.0E+00

3.0E-01

6.0E-01

9.0E-01

1.2E+00

1.5E+00

1.0E+07 2.0E+07 3.0E+07 4.0E+07 5.0E+07 6.0E+07

SystmPAT79RI 99KGU00LAS75KYU79MOH84ANL87BRC81LAS75KOS81FEI89FEI89SAV98BRC02RI 99LAS75AUB76JAE93LAS77AEP89

Validation: SACS Validation: C/E

Cross sections

•816 targets (H-1 to Fm-257)•86 reaction types

•2,233 nuclides•Stables and isomeric states (T½ > 1s)

Decay data

EAF-2010

5096 important reactions

2265 major reactions

1728 reactions with any experimental data

66256 neutron induced reactions

470 reactions with integral data

EAF-2010

• The files are ready for distribution:

cross sections, uncertainty file, decay data, hazard indices,…

• The documentation is been finalized

• With updates on the FISPACT code it will form part of EASY-2010

• Validation & Verification tasks have already started

Concluding remarks

• EAF-2010 will be the last of a generation of EAF files• The approach has combined TALYS derived data with

careful and experienced evaluation using EXFOR and the SAFEPAQ evaluation/visualisation tool.

• It will be the most complete and improved version of the EAF generation

• For the future there is a strong desire to combine activation and transport calculations using complete and consistent data libraries (unique)

• Now its time to move towards this goal by taking the best data and approaches available