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Evaluated Gamma-ray Activation File (EGAF)

Evaluated Gamma-ray Activation File (EGAF). Richard B. Firestone Isotopes Project, Lawrence Berkeley National Laboratory, Berkeley, CA 94720. IAEA NSDD Meeting, 4-8 April 2011, Vienna. EGAF Capture Gamma Ray Collaboration. Isotopes Project (LBNL) - R.B. Firestone, A. Hurst, S. Basunia

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Evaluated Gamma-ray Activation File (EGAF)

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  1. Evaluated Gamma-ray Activation File (EGAF) Richard B. Firestone Isotopes Project, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 IAEA NSDD Meeting, 4-8 April 2011, Vienna

  2. EGAF Capture Gamma Ray Collaboration • Isotopes Project (LBNL) - R.B. Firestone, A. Hurst, S. Basunia • LLNL Nuclear Data Library – B. Sleaford, N. Summers • Budapest Reactor – Zs. Revay, T. Belgya, L. Szentmiklosi • NIF STARS/LiBeRACE Collaboration – • L. Bernstein, D. Bleuel, J.A. Caggiano, D.H.G. Schneider, W. Stoeffl (LLNL) • M. Wiedeking (iThemba Labs, South Africa) • M. Krticka (Charles University, Prague) • S. Siem, A. Goergen, M. Guttormsen, A.C. Larsen (U. Oslo) • C. Beausang (University of Richmond) • IAEA Nuclear Data Section –D. Abriola, R. Capote, M. Kellett, V. Zerkin

  3. History of EGAF Before 1996 no reliable sg database was available. • 1996: At CGS9 (Budapest) initial discussions begin on the development of a k0/sg database based on Budapest Reactor measurements. • 1998 – 2003: IAEA CRP on Development of a Database for Prompt Gamma-ray Neutron Activation Analysis. First evaluation of prompt k0/sg database. • 2004: Publication of the Handbook of Prompt Gamma Activation Analysis (Kluwer Publishers). Budapest prompt sg data and spectra for all elements. • 2006: Release of EGAF database IAEA - http://www-nds.iaea.org/pgaa/pgaa7/index.html LBNL - http://ie.lbl.gov/PGAA/PGAASearch.asp • 2007: IAEA Publication of the Database of Prompt Gamma Rays from Slow Neutron Capture for Elemental Analysis. Results of IAEA CRP. http://www-pub.iaea.org/MTCD/publications/PDF/Pub1263_web.pdf. • 2006 – 2010: IAEA CRP on Reference Database for Neutron Activation Analysis. Intercomparison of literature, EGAF and IUPAC sg/k0/s0 data. • 2006 – present: Evaluation of EGAF 2 begins. • 2008: LLNL/LBNL collaboration for an ENDF capture g-ray library. • 2009: LBNL Isotopes Project begins evaluation of Reaction Input Parameter Library (RIPL) data • 2010: LBNL begins discussion of evaluation of activation data for the DDEP.

  4. EGAF Database Content Prompt thermal (n,g) data • Capture g-ray energies Eg • Capture g-ray thermal cross sections sg • PGAA k0 factors • Recommended Ig per 100 neutron captures • Neutron separation energies SN • Thermal neutron capure state widths Gg • RIPL nuclear structure data • Recommended Jp values from experiment and theory • New Jp values from statistical model calculations • Improved level g-ray branching intensities Activation thermal (n,g) data • Energies and tranistion probabilities Eg, Pg • Normalization to g-ray cross sections, sg • NAA k0 factors calculated from sg and Pg Total radiative cross sections s0 • Compilation of measured values (corrected for new standard data) • New values derived from prompt (n,g) data and statistical model calculations • Recommended values from all data

  5. Neutron beam measurements - Budapest Reactor and neutron guide hall. The PGAA (capture g-ray) station is located 30 m from the reactor wall where backgrounds are low. Compton suppression ≈5 (1332 keV) to ≈40 (7000 keV) HPGe efficiency precision <1% for E=0.5-6 MeV, <3% 0.05-0.5 MeV and >6 MeV. Neutron flux is 1.2108 n/cm2

  6. Neutron beam measurements - Munich • New experiments planned at Munich for 2011 (2H, 3He, 90Zr) • 7.3109 n/cm2 at target position (14 mm38 mm beam) • 21010 n/cm2 at He gas-flushed elliptical guide (4 mm10 mm beam)

  7. Cross section standardization methods • Stoichiometric compounds containing elements with well-known cross sections: H, N, Cl, S, Na, Ti, Au KCl, (CH2)n, Pb(NO3)2, Tl2SO4 • Homogenous mixtures Aqueous (H2O) or acid (20% HCl) solutions Mixed powders (TiO2) • Activation products with well-known Pg 19F, 28Al, 100Tc, 235U Measurements have been completed on all elemental targets Z=1-83, 92 except for He and Pm and on the radioactive targets 99Tc, and 129I

  8. The k0 PGAA/NAA Method Relative g-ray intensities measured in PGAA/NAA from different elements can be converted to relative masses using the g-ray k0 factors.

  9. EGAF Database Sources IAEA Database of Prompt Gamma Rays from Slow Neutron Capture for Elemental Analysis PGAA-IAEA Database Viewer

  10. EGAF Data Analysis Hypermet peak analysis • Budapest Reactor Capture g-ray spectrum • Analyzed spectrum using Hypermet • Place g-rays in ENSDF format (n,g) dataset • Normalize data to Budapest cross section • Check intensity balance for problems • Determine s0, SN, …. • Analyze activation data from ENSDF, DDEP

  11. s(in) s(out) 0.0 3.86 1.24 1.22 0.016 0.016 3.85 0.0 Total radiative cross sections (s0) For complete low-Z level schemes s0 are determined from EGAF sg data Comparison of 12C s0 values

  12. Determining s0 for complex level schemes • Below Ecrit all nuclear structure is known (RIPL) • All primary g-ray to levels below Ecrit are measured (Budapest) • The rest of the levels and g-rays can be calculated with DICEBOX • s0 = s0(GS)obs + s0(GS)stat Population/Depopulation plot

  13. Palladium Isotopes Results* * M. Krticka, R.B. Firestone, D.P. McNabb, B. Sleaford, U. Agvaanluvsan, T. Belgya, and Z.S. Revay, Phys. Rev. C 77, 054615 (2008).

  14. IUPAC NAA k0 Database • Based on measurements of Frans De Corte and Andras Simonits, Atomic Data and Nuclear Data Tables 85 (2003) 47–67. • Adopted by International Union of Pure and Applied Chemistry, Pure Appl. Chem., Vol. 76, No. 10, pp. 1921–1925, 2004. • Contains recommended “experimental” k0 values that have not been “evaluated” by comparison with other cross section measurements. • A k0 committee led by Zsolt Revay has been formed to look into updating the database • Tradition dictates a “pure” experimental approach. • The evaluation community favors a data comparison. • This led to the IAEA CRP “Reference Database for NAA” • An IAEA consultants meeting next week will discuss how to proceed. • Any one interested can join an informal discuss this week.

  15. 3rd IAEA Research Coordination Meeting on “Reference Database for NAA” Comparison of selected IUPAC(k0), Atlas(s0), and EGAF(sg) PGAA/NAA data 24Nag s0(NAA) 542(3) mb s0(PGAA)540(4) mb s0 (Atlas)517(4) mb 24Nam s0(NAA)478(4) mb s0(Atlas) 400(3) mb 36S k0(NAA) 3.05(10)10-6 k0(IUPAC)1.96(4)10-6 K 41Ks0(PGAA)2.21(3) b s0(Atlas)2.1(2) b 40K s0(PGAA)90(3) b s0(Atlas)30(8) b 42K s0(PGAA) 1.522(22) b s0(Atlas)1.46(3) b 31Si(Eg=1266 keV) Pg(ENSDF) 0.00050(4) Pg(PGAA) 0.000589(12) 45Scm s0(NAA)7.77(21) b s0(Atlas)9.9(11) b 70Zn s0(NAA)83(5) mb s0(Atlas)22 mb 127I s0(IUPAC) 5.48(12) b s0(Atlas)6.15(6) or for Eg=443 keV Pg(ENSDF)0.1261(8) Pg(Atlas)0.112(3) 186W s0(NAA)34.8(2) b s0(Atlas)38.1(5) b • 114mIn(t1/2=49.51 d) • ENSDF • %IT 96.75(24) • %EC+b+ 3.25(24) • EGAF-NAA • %IT 95.72(7) • %EC+b+ 4.28(7)

  16. Proposed EGAF Publication in NDS • EGAF Publication Considerations • First publish sg data in refereed journals • Then publish detailed EGAF evaluation in NDS • Adopted EGAF dataset – Eg, sg, k0, s0, Sn, RIPL levels • Supporting datasets – Eg, Ig • Activation decay datasets – Eg, Pg, sg, k0 • Finally provide updated EGAF database to IAEA • Why Nuclear Data Sheets? • Existing NDS production procedures are satisfactory • Most suitable journal for nuclear data publication • Detailed information on EGAF evaluation not in journal

  17. Comments

  18. General comments – s0 summary Summary of s0 values from the literature (CSISRS) and this evaluation

  19. RIPL Adopted Level Data Cross section balance through the (n,g) level scheme. Justification of RIPL Jp assignments.

  20. Adopted sg, k0 Data Both g-ray cross sections and k0 values

  21. Level scheme drawing Possibly too complex?

  22. Supporting Budapest sg Dataset Primary sgdata source. Other important datasets from the literature will be included.

  23. Adopted Ig per 100 neutron captures table Ig per 100 neutron captures normalized to s0

  24. Activation decay data Pg on table, conversion factor to sg on drawing

  25. Adopted RIPL Nuclear Structure File

  26. ENDF GND ENSDF Other Data AME Masses XUNDL, EGAF Atomic data Applications RIPL LLNL – ENDF/ENSDF Database Project LLNL has begun a 5-year USDOE funded project to develop a General Nuclear Database that will include ENDF, ENSDF, and other databases using Extensible Markup Language (XML) to serve these data to various applications. • ENSDF input • physics checking • Automatic AME updating Replacement of ENSDF “card image” structure with modern XML capabilities. Future “home” of RIPL and EGAF

  27. Future Considerations • Recommendations • Publish new elemental evaluations in Nuclear Data Sheets after prompt g-ray journal publication • Publish activation data in DDEP Table of Radionuclides • ENSDF proposals • Provide g-ray cross section normalization to barns • Include Gg on primary capture g-ray and calculate reduced transition probabilities. • IUPAC NAA k0 database • Provide recommended Eg, t1/2 data from ENSDF/DDEP • Compare recommended k0 values with EGAF evaluation • Supplement k0 database with complete g-ray list.

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