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1. Nuclear Data. Prof. Dr. A.J. (Arjan) Koning 1,2 1 International Atomic Energy Agency, Vienna 2 Division of Applied Nuclear Physics, Department of Physics and Astronomy, Uppsala University, Uppsala, Sweden Email: A.koning @iaea.org. EXTEND
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1. Nuclear Data Prof. Dr. A.J. (Arjan) Koning1,2 1International Atomic Energy Agency, Vienna 2Division of Applied Nuclear Physics, Department of Physics and Astronomy, Uppsala University, Uppsala, Sweden Email:A.koning@iaea.org EXTEND European School on Experiment, Theory and Evaluation of Nuclear Data, Uppsala University, Sweden, August 29 - September 2, 2016
Nuclear data for applications • Alleffects ofaninteraction of a particle (usually: neutron) with a nucleus in numerical form: • Cross sections (total, elastic, inelastic, (n,2n), fission, etc.) • Angulardistributions (elastic, inelastic, etc.) • Emission energy spectra • Gamma-rayproduction • Fissionyields, number of prompt/delayed neutrons • Radioactivedecay data • Etc. • Complete nuclear data librariescanbeobtainedthrough a combination of experimental and theoretical (computational) nuclearphysics
Introduction • Nuclear data is crucialfor reactor and fuelcycle analysis: • Energy production, radiationdamage, radioactivity, etc. • Currently large emphasis on uncertainties: nuclear data uncertainites lead touncertainties in key performance parameters • More complete and accurate nuclear data foradvanced reactor systems does not prove the principle, but • Acceleratesdevelopmentwith minimum of safety-justifying steps • improves the economywhilstmaintainingsafety • The nuclearindustry claims thatimprovednuclear data, and associateduncertainty assessment, still has economical benefits of hundreds of million per year
Nuclear data needs and tools • A well-balanced effort is requiredfor: • High accuracydifferentialmeasurements(Europe: IRMM Geel + CERN-nTOF + others) • Nuclear model development and software (Europe: TALYS) • Data evaluation, uncertainty assessment and libraryproduction and processing (Europe: JEFF, TENDL) • Validationwithsimple (criticality, shielding) and complex (entire reactors) integralexperiments • Allthis is neededforbothfission and fusion: the approach is similar, the energy range is different.
Nuclear data cycle Or TENDL!!
Why do weneednuclear data and how accurate ? Nuclear data needed for Understanding basic reaction mechanism between particles and nuclei Astrophysical applications (Age of the Galaxy, element abundances …) Existing or future nuclear reactor simulations Medical applications, oil well logging, waste transmutation, fusion, … But Finite number of experimental data (price, safety or counting rates) Complete measurements restricted to low energies ( < 1 MeV) to scarce nuclei Predictive & Robust Nuclear models (codes) are essential
EXFOR database (Nuclear Reaction Data Center Network: IAEA, NEA, NNDC, JAEA, Obninsk, etc) Total estimated cost of EXFOR (AK, private comm.): between 20 – 60 Billion Euro Total estimated value of EXFOR : priceless
TYPES OF DATA NEEDED Cross sections : total, reaction, elastic (shape & compound), non-elastic, inelastic (discrete levels & total) total particle (residual) production all exclusive reactions (n,nd2a) all exclusive isomer production all exclusive discrete and continuum g-ray production Spectra : elastic and inelastic angular distribution or energy spectra all exclusive double-differential spectra total particle production spectra compound and pre-equilibrium spectra per reaction stage. Fission observables : cross sections (total, per chance) fission fragment mass and isotopic yields fission neutrons (multiplicities, spectra) Miscellaneous : recoil cross sections and ddx particle multiplicities astrophysicalreaction rates covariance information
DATA FORMAT • Trivial for basic nuclear science : x,y,(z) file • Complicated (evencrazy) for data production issues : ENDF file
Content nature (s) Target mass Target identification (151Sm) Values Content type (n,2n) Number of values Material number DATA FORMAT : ENDF file • Trivial for basic nuclear science : x,y,(z) file • Complicated (evencrazy) for data production issues : ENDF file
Automating nuclear science Road to success: • Use (extremely) robust software • Store all human intelligence per isotope in input files and scripts
The total TALYS code system • TALYS: Nuclear model code, Fortran, 110,000 lines(open source, NRG + CEA-DAM) • TEFAL: ENDF-6/EAF formatting code, Fortran, 15,000 lines(AK) • TASMAN: Optimization and covariance program for TALYS, Fortran 10,000 lines(AK) • TARES: Resonance data and covariance generator, C++ 10,000 lines(DR) • TAFIS: code for data and covariance of averagenumber of fission neutrons, C++ and Fortran, 3,000 lines(DR) • TANES: code forfission neutron spectra and covariances, C++ and Fortran, 3,000 lines (includes RIPL code) (DR) • AUTOTALYS: script touse the above codes and toproducenuclear data libraries in a systematicmanner(AK) This is allneededtobringbasic nucleardata totechnology