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 Kopecky JUKO 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 ( 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 –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 –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  ( 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 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 and TALYS generated libraries, Fus. Eng. Des

Analysis options: Distinguish Threshold Reactions

Defining skewness for threshold reactions 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 Calculated quantities

Generate cross section data tool: 7 reaction types enabled

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

Error handling: all required trendlines are not stored

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

Cubic fit to E th, E low and E max 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

Option 1: Quartic fit to E max, E high and E 30 ; exponential fit to 30 and 60 MeV

Option 2: Cubic fit to E max and E high ; exponential fit to E high and 60 MeV

Options 4 and 5: Lorentzian fit to parameters Standard Lorentzian: Modified Lorentzian:

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

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.

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 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