EAF-2010 – the best of a generation

1. EAF-2010 – the best of a generation Jean-Christophe Sublet, Lee Packer Euratom/CCFE Fusion AssociationCulham Science Centre and Jura Kopecky JUKO Research CCFE is the fusion research arm of the United Kingdom Atomic Energy Authority

2. 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

3. 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

4. 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

5. 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.

6. 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 s(0.0253 eV) and RI with corresponding C/E values.

7. 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

8. 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).

9. Neutron-induced reactions • Reactions that tend to be most important for fusion applications are: • (n,2n) – neutron multiplication • (n,p) - produces hydrogen • (n,a) - produces helium • (n,g) • (n,n') – for isomeric states • However, other reaction types can be important data for 86 reaction types

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

11. Analysis options: Distinguish Threshold Reactions

12. Defining skewness for threshold reactions Skewness parameter,

13. SACS: Skewness parameter implementation

14. 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.

15. 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.

16. Cross section parameters

17. Generate cross section data tool Calculatedquantities Fitting options

18. Generate cross section data tool: 7 reaction types enabled

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

20. Error handling: all required trendlines are not stored

21. Error handling: all required trendlines are not stored

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

23. Cubic fit to Eth, Elow and Emax • Determine A-1 using Gauss-Jordan elimination method and multiply by b matrix  solution to cubic coefficients. Fits well over asymmetry range 0.01 – 0.25

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

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

26. Options 4 and 5: Lorentzian fit to parameters • Standard Lorentzian: • Modified Lorentzian:

27. 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 ds/dE=0 at Emax • Option 5: passing through El, Emax and Eh

28. Small improvements: omit systematic error bars

29. 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.

30. 2,233 nuclides • Stables and isomeric states (T½ > 1s) • 816 targets (H-1 to Fm-257) • 86 reaction types Cross sections Decay data Validation: SACS Validation: C/E

31. 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

32. 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