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Transcript of Evaluated Gamma-ray Activation File (EGAF) Richard B. Firestone Isotopes Project, Lawrence Berkeley...
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.