Evaluated Gammaray Activation File EGAF Richard B Firestone

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 LLNL Nuclear Data Library – B. Sleaford, N. Summers Budapest Reactor – Zs. Revay, T. Belgya, L. Szentmiklosi NIF STARS/Li. Be. RACE Collaboration – L. Bernstein, D. Bleuel, J. A. Caggiano, D. H. G. Schneider, W. Stoeffl (LLNL) M. Wiedeking (i. Themba 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

History of EGAF Before 1996 no reliable sg database was available. • • • 1996: At CGS 9 (Budapest) initial discussions begin on the development of a k 0/sg databased on Budapest Reactor measurements. 1998 – 2003: IAEA CRP on Development of a Database for Prompt Gammaray Neutron Activation Analysis. First evaluation of prompt k 0/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 7/index. html LBNL - http: //ie. lbl. gov/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/Pub 1263_web. pdf. 2006 – 2010: IAEA CRP on Reference Database for Neutron Activation Analysis. Intercomparison of literature, EGAF and IUPAC sg/k 0/s 0 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.

EGAF Database Content Prompt thermal (n, g) data • Capture g-ray energies Eg • Capture g-ray thermal cross sections sg • PGAA k 0 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 k 0 factors calculated from sg and Pg Total radiative cross sections s 0 • 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

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 ke. V) to ≈40 (7000 ke. V) HPGe efficiency precision <1% for E=0. 5 -6 Me. V, <3% 0. 05 -0. 5 Me. V and >6 Me. V. Neutron flux is 1. 2 108 n/cm 2

Neutron beam measurements - Munich New experiments planned at Munich for 2011 (2 H, 3 He, 90 Zr) 7. 3 109 n/cm 2 at target position (14 mm 38 mm beam) 2 1010 n/cm 2 at He gas-flushed elliptical guide (4 mm 10 mm beam)

Cross section standardization methods 1. Stoichiometric compounds containing elements with well-known cross sections: H, N, Cl, S, Na, Ti, Au KCl, (CH 2)n, Pb(NO 3)2, Tl 2 SO 4 2. Homogenous mixtures Aqueous (H 2 O) or acid (20% HCl) solutions Mixed powders (Ti. O 2) 3. Activation products with well-known Pg 19 F, 28 Al, 100 Tc, 235 U Measurements have been completed on all elemental targets Z=1 -83, 92 except for He and Pm and on the radioactive targets 99 Tc, and 129 I

The k 0 PGAA/NAA Method Relative g-ray intensities measured in PGAA/NAA from different elements can be converted to relative masses using the g-ray k 0 factors.

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

EGAF Data Analysis Hypermet peak analysis Budapest Reactor Capture g-ray spectrum 1. 2. 3. 4. 5. 6. 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 s 0, SN, …. Analyze activation data from ENSDF, DDEP

Total radiative cross sections (s 0) For complete low-Z level schemes s 0 are determined from EGAF sg data s(in) s(out) 0. 0 3. 86 1. 24 1. 22 0. 016 3. 85 0. 0 Comparison of 12 C s 0 values Author (Year) Prestwich (1981) Jurney (1982) Nichols (1960) Sagot (1963) Jurney (1963) Starr (1962) Hennig (1967) Matsue (2004) EGAF (2007) Mughab Atlas s 0±Ds (mb) 3. 50± 0. 16 3. 53± 0. 07 3. 57± 0. 03 3. 72± 0. 15 3. 8± 0. 4 3. 83± 0. 06 3. 85± 0. 15 3. 81± 0. 11 3. 85± 0. 06 3. 53± 0. 07

Determining s 0 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 • s 0 = s 0(GS)obs + s 0(GS)stat Population/Depopulation plot

Palladium Isotopes Results* Isotope s 0(literature) (b) s 0(this work) (b) 102 Pd(n, g)103 Pd 1. 6± 0. 2 1. 1± 0. 4 104 Pd(n, g)105 Pd 0. 65± 0. 30 0. 75± 0. 26 105 Pd(n, g)106 Pd 21. 0± 1. 5 21. 7± 0. 5 106 Pd(n, g)107 Pd 0. 30± 0. 03 0. 36± 0. 10 108 Pd(n, g)109 g. Pd 7. 6± 0. 5 8. 6± 0. 6 108 Pd(n, g)109 m. Pd 0. 185± 0. 011 0. 185± 0. 010 110 Pd(n, g)111 Pd 0. 70± 0. 17 0. 34± 0. 10 * M. Krticka, R. B. Firestone, D. P. Mc. Nabb, B. Sleaford, U. Agvaanluvsan, T. Belgya, and Z. S. Revay, Phys. Rev. C 77, 054615 (2008).

IUPAC NAA k 0 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” k 0 values that have not been “evaluated” by comparison with other cross section measurements. • A k 0 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.

3 rd IAEA Research Coordination Meeting on “Reference Database for NAA” s 0(NAA) s 0(PGAA) s 0 (Atlas) s 0(NAA) s 0(Atlas) Comparison of selected IUPAC(k 0), Atlas(s 0), and EGAF(sg) 24 Nag 31 Si(E =1266 ke. V) PGAA/NAA data g 542(3) mb 540(4) mb 517(4) mb 24 Nam 478(4) mb 400(3) mb 36 S k 0(NAA) 3. 05(10) 10 -6 k 0(IUPAC) 1. 96(4) 10 -6 K 41 K s (PGAA) 2. 21(3) b 0 s 0(Atlas) 2. 1(2) b 40 K s (PGAA) 90(3) b 0 s 0(Atlas) 30(8) b 42 K s (PGAA) 1. 522(22) b 0 s 0(Atlas) 1. 46(3) b Pg(ENSDF) 0. 00050(4) 114 m. In(t =49. 51 d) 1/2 Pg(PGAA) 0. 000589(12) ENSDF 45 Scm %IT 96. 75(24) s 0(NAA) 7. 77(21) b %EC+b+ 3. 25(24) s 0(Atlas) 9. 9(11) b EGAF-NAA 70 Zn %IT 95. 72(7) s 0(NAA) 83(5) mb %EC+b+ 4. 28(7) s 0(Atlas) 22 mb 127 I s 0(IUPAC) 5. 48(12) b s 0(155 Gd(n, g)156 Gd) s 0(Atlas) 6. 15(6) Atlas 60, 900(500) or for Eg=443 ke. V EGAF 66, 200(4, 100) Pg(ENSDF) 0. 1261(8) Pg(Atlas) 0. 112(3) s 0 (157 Gd(n, g)158 Gd) 186 W Atlas 254000(815) s 0(NAA) 34. 8(2) b EGAF 216000(5000) s 0(Atlas) 38. 1(5) b

Proposed EGAF Publication in NDS EGAF Publication Considerations First publish sg data in refereed journals Then publish detailed EGAF evaluation in NDS a. Adopted EGAF dataset – Eg, sg, k 0, s 0, Sn, RIPL levels b. Supporting datasets – Eg, Ig c. Activation decay datasets – Eg, Pg, sg, k 0 3. Finally provide updated EGAF database to IAEA 1. 2. 3. Why Nuclear Data Sheets? 1. Existing NDS production procedures are satisfactory 2. Most suitable journal for nuclear data publication 3. Detailed information on EGAF evaluation not in journal

Comments

General comments – s 0 summary Summary of s 0 values from the literature (CSISRS) and this evaluation

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

Adopted sg, k 0 Data Both g-ray cross sections and k 0 values

Level scheme drawing Possibly too complex?

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

Adopted Ig per 100 neutron captures table Ig per 100 neutron captures normalized to s 0

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

Adopted RIPL Nuclear Structure File

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. Other Data ENSDF AME Masses XUNDL, EGAF Atomic data ENDF Future “home” of RIPL and EGAF GND RIPL • ENSDF input • physics checking • Automatic AME updating Applications Replacement of ENSDF “card image” structure with modern XML capabilities.

Future Considerations Recommendations 1. Publish new elemental evaluations in Nuclear Data Sheets after prompt g-ray journal publication 2. Publish activation data in DDEP Table of Radionuclides 3. ENSDF proposals • Provide g-ray cross section normalization to barns • Include Gg on primary capture g-ray and calculate reduced transition probabilities. 4. IUPAC NAA k 0 database • Provide recommended Eg, t 1/2 data from ENSDF/DDEP • Compare recommended k 0 values with EGAF evaluation • Supplement k 0 database with complete g-ray list.