Evaluated Gamma-ray Activation File Evaluated Gamma-ray Activation File (EGAF)(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/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

History of EGAF

Before 1996 no reliable database was available.

• 1996: At CGS9 (Budapest) initial discussions begin on the development of a k0/ 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/ database.

• 2004: Publication of the Handbook of Prompt Gamma Activation Analysis (Kluwer Publishers). Budapest prompt data and spectra for all elements.

• 2006: Release of EGAF databaseIAEA - http://www-nds.iaea.org/pgaa/pgaa7/index.htmlLBNL - 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 /k0/0 data.• 2006 – present: Evaluation of EGAF 2 begins.• 2008: LLNL/LBNL collaboration for an ENDF capture -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,) data• Capture -ray energies E

• Capture -ray thermal cross sections

• PGAA k0 factors• Recommended I per 100 neutron captures• Neutron separation energies SN • Thermal neutron capure state widths

• RIPL nuclear structure data- Recommended J values from experiment and theory- New J values from statistical model calculations- Improved level -ray branching intensities

Activation thermal (n,) data• Energies and tranistion probabilities E, P • Normalization to -ray cross sections,

• NAA k0 factors calculated from and P

Total radiative cross sections

• Compilation of measured values (corrected for new standard data)• New values derived from prompt (n,) data and statistical model calculations• Recommended values from all data

Neutron beam measurements - Budapest

Reactor and neutron guide hall. The PGAA (capture -ray) station is located 30 m from the reactor wall where backgrounds are low.

HPGe efficiency precision <1% for E=0.5-6 MeV, <3% 0.05-0.5 MeV and >6 MeV.

Compton suppression ≈5 (1332 keV) to ≈40 (7000 keV)

Neutron flux is 1.2108 n/cm2

Neutron beam measurements - Munich

New experiments planned at Munich for 2011 (2H, 3He, 90Zr)

7.3109 n/cm2 at target position (14 mm38 mm beam)

21010 n/cm2 at He gas-flushed elliptical guide (4 mm10 mm beam)

Cross section standardization methodsCross section standardization methods

1. Stoichiometric compounds containing elements with well-known cross sections: H, N, Cl, S, Na, Ti, Au

KCl, (CH2)n, Pb(NO3)2, Tl2SO4

2. Homogenous mixtures

Aqueous (H2O) or acid (20% HCl) solutions

Mixed powders (TiO2)

3. Activation products with well-known P

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

The k0 PGAA/NAA Method

P

0.9558) (Au)P ,0.1(H)(Py probabilittion ray transiγP

b) 98.65 b, 3326.0(section crossneutron thermal

100) ,9985.99( abundance isotopic

196.9655) 1.00794,( mass atomic

comparator )Au(411.802 analyteNAA

comparator )H(2223.25 analytePGAA

)(

x0,

4112223

Au0,,0,0

Au

,0

,0,0

Hx

H

AuH

HHHx

xxHH

MMM

x

PM

PMk

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

EGAF Database SourcesEGAF 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 -ray spectrum

1. Analyzed spectrum using Hypermet2. Place -rays in ENSDF format (n,) dataset3. Normalize data to Budapest cross section4. Check intensity balance for problems5. Determine , SN, ….6. Analyze activation data from ENSDF, DDEP

Total radiative cross sections (

(in) (out)

0.0 3.86

1.24 1.22

0.016 0.016

3.85 0.0

For complete low-Z level schemes are determined from EGAF data

(GS)∑=(primary)∑=0 γσγσσ

Author (Year) 0 (mb)

Prestwich (1981) 3.50±0.16Jurney (1982) 3.53±0.07Nichols (1960) 3.57±0.03Sagot (1963) 3.72±0.15Jurney (1963) 3.8±0.4Starr (1962) 3.83±0.06

Hennig (1967) 3.85±0.15Matsue (2004) 3.81±0.11EGAF (2007) 3.85±0.06

Mughabghab Atlas 3.53±0.07

Comparison of 12C values

Determining for complex level schemes

• Below Ecrit all nuclear structure is known (RIPL)• All primary -ray to levels below Ecrit are measured (Budapest)• The rest of the levels and -rays can be calculated with DICEBOX• = (GS)obs + (GS)stat

Population/Depopulation plot

Palladium Isotopes Results*Palladium Isotopes Results*

Isotope (literature) (b) (this work) (b)

102Pd(n,)103Pd 1.6±0.2 1.1±0.4104Pd(n,)105Pd 0.65±0.30 0.75±0.26105Pd(n,)106Pd 21.0±1.5 21.7±0.5106Pd(n,)107Pd 0.30±0.03 0.36±0.10

108Pd(n,)109gPd 7.6±0.5 8.6±0.6108Pd(n,)109mPd 0.185±0.011 0.185±0.010110Pd(n,)111Pd 0.70±0.17 0.34±0.10

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

IUPAC NAA k0 DatabaseIUPAC 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”“Reference Database for NAA”• An IAEA consultants meeting next week will discuss how to proceed.An IAEA consultants meeting next week will discuss how to proceed.• Any one interested can join an informal discuss this week.Any one interested can join an informal discuss this week.

3rd IAEA Research Coordination Meeting on 3rd IAEA Research Coordination Meeting on “Reference Database for NAA”“Reference Database for NAA”

24Nag

(NAA) 542(3) mb

0(PGAA) 540(4) mb

(Atlas) 517(4) mb24Nam

(NAA) 478(4) mb

(Atlas) 400(3) mb36S

k0(NAA) 3.05(10)10-6 k0(IUPAC) 1.96(4)10-6

K 41K (PGAA) 2.21(3) b(Atlas) 2.1(2) b40K (PGAA) 90(3) b(Atlas) 30(8) b42K (PGAA) 1.522(22) b(Atlas) 1.46(3) b

31Si(E=1266 keV)P(ENSDF) 0.00050(4)P(PGAA) 0.000589(12)

45Scm

(NAA) 7.77(21) b(Atlas) 9.9(11) b

70Zn(NAA) 83(5) mb(Atlas) 22 mb

127I(IUPAC) 5.48(12) b(Atlas) 6.15(6)

or for E=443 keVP(ENSDF) 0.1261(8)P(Atlas) 0.112(3)

186W(NAA) 34.8(2) b(Atlas) 38.1(5) b

Comparison of selected IUPAC(k0), Atlas(), and EGAF() PGAA/NAA data

114mIn(t1/2=49.51 d)ENSDF

%IT 96.75(24)%EC+ 3.25(24)

EGAF-NAA%IT 95.72(7)%EC++ 4.28(7)

(155Gd(n,)156Gd)

Atlas 60,900(500)

EGAF 66,200(4,100)

(157Gd(n,)158Gd)

Atlas 254000(815)EGAF 216000(5000)

Proposed EGAF Publication in NDS

EGAF Publication Considerations

1. First publish data in refereed journals

2. Then publish detailed EGAF evaluation in NDSa. Adopted EGAF dataset – E, , k0, , Sn, RIPL levels

b. Supporting datasets – E, Ig

c. Activation decay datasets – E, P, , k0

3. Finally provide updated EGAF database to IAEA

Why Nuclear Data Sheets?

1. Existing NDS production procedures are satisfactory2. Most suitable journal for nuclear data publication3. Detailed information on EGAF evaluation not in journal

Comments

General comments – summary

Summary of values from the literature (CSISRS) and this evaluation

RIPL Adopted Level Data

Cross section balance through the (n,) level scheme.

Justification of RIPL J assignments.

Adopted , k0 Data

Both -ray cross sections and k0 values

Level scheme drawing

Possibly too complex?

Supporting Budapest Dataset

Primary data source.

Other important datasets from the literature will be included.

Adopted I per 100 neutron captures table

I per 100 neutron captures normalized to

Activation decay data

P on table, conversion factor to 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.

ApplicationsENDF GND

ENSDF

RIPL

Other DataAME Masses

XUNDL, EGAFAtomic data

• ENSDF input • physics checking• Automatic AME updating

Replacement of ENSDF “card image” structure with modern XML capabilities.Future “home” of

RIPL and EGAF

Future Considerations

Recommendations

1. Publish new elemental evaluations in Nuclear Data Sheets after prompt -ray journal publication

2. Publish activation data in DDEP Table of Radionuclides

3. ENSDF proposals

• Provide -ray cross section normalization to barns

• Include on primary capture -ray and calculate reduced transition probabilities.

4. IUPAC NAA k0 database

• Provide recommended E, t1/2 data from ENSDF/DDEP

• Compare recommended k0 values with EGAF evaluation

• Supplement k0 database with complete -ray list.