INTERNATIONAL ATOMIC ENERGY AGENCY NUCLEAR DATA SERVICES DOCUMENTATION SERIES OF THE IAEA NUCLEAR DATA SECTION

IAEA-NDS-173
Rev. 1, October 1998

FENDL/A2.0
Neutron Activation Cross Section Data Library for Fusion Applications

Released on March 14, 1997

Prepared by

A.B. Pashchenko and H. Wienke
IAEA Nuclear Data Section

J. Kopecky ^*)
Netherlands Energy Research Foundation, ECN, Petten

J.-Ch. Sublet and R.A. Forrest
UKAEA Fusion (Euratom/UKAEA Fusion Association)
Culham, Abingdon, Oxfordshire OX14 3DB, U.K.

^*) Present address: JUKO Research, Alkmaar, Netherlands.

Abstract: This document describes the contents of a comprehensive neutron cross section data library for 13,006 neutron activation reactions with 739 target nuclides from H (A=1,Z=1) to Cm (A=248,Z=96), in the incident energy range up to 20 MeV. FENDL/A2 is a sublibrary of FENDL-2, the second revision of the evaluated nuclear data library for fusion applications. It is supplemented by a decay data library FENDL/D-2 in ENDF-6 format for 1867 nuclides. The data are available from the IAEA Nuclear Data Section online via INTERNET, or on magnetic tape upon request.

Note:

The IAEA-NDS-reports should not be considered as formal publications. When a nuclear data library is sent out by the IAEA Nuclear Data Section, it will be accompanied by an IAEA-NDS-report which should give the data user all necessary documentation on contents, format and origin of the data library.

IAEA-NDS-reports are updated whenever there is additional information of relevance to the users of the data library.

For citations care should be taken that credit is given to the author of the data library and/or to the data center which issued the data library. The editor of the IAEA-NDS-report is usually not the author of the data library.

Neither the originator of the data libraries nor the IAEA assume any liability for their correctness or for any damages resulting from their use.

96/11

Citation guideline:

This data library should be cited as follows:

A.B. Pashchenko et al., "FENDL/A-2.0 Neutron activation cross section data library for fusion applications", report IAEA(NDS)-173 (IAEA October 1998). Data library retrieved online (or: received on tape) from the IAEA Nuclear Data Section.

FENDL/A2.0
Neutron Activation Cross Section Data Library for Fusion Applications

Released on March 14, 1997

Prepared by
A.B. Pashchenko and H. Wienke
IAEA Nuclear Data Section

J. Kopecky ^*)
Netherlands Energy Research Foundation, ECN, Petten

J.-Ch. Sublet and R.A. Forrest
UKAEA Fusion (Euratom/UKAEA Fusion Association)
Culham, Abingdon, Oxfordshire OX14 3DB, U.K.

^*) Present address: JUKO Research, Alkmaar, The Netherlands

1. Introduction

This neutron activation cross section data base was produced within the IAEA FENDL project which has the goal of providing a comprehensive Fusion Evaluated Nuclear Data Library for predicting all nuclear processes in fusion devices such as the International Thermonuclear Experimental Reactor, ITER. The FENDL library is composed of several sublibraries describing the transport of both the plasma-source neutrons and secondary gamma rays through fusion device components, as well as the resulting radiation effects, such as nuclear heating, tritium generation, activation and material damage. Complementing the activation cross section library is the decay data library which, within the FENDL project, has the designator FENDL/D. It is also briefly described in the current document.

2. History of the FENDL/A files family

The FENDL activation programme was started in May 1989 at the FENDL meeting [1], when the Working Group on Neutron Activation Data initiated an intercomparison of activation cross sections important for fusion technology.

It was agreed that national nuclear data centres and research laboratories would send to the Nuclear Data Section their contributions, according to a list of reactions selected on the basis of inventory calculations. This activity resulted in 1994 in the release of the activation sublibrary FENDL/A-1.1 [2], as a part of the general FENDL-1 library.

During the IAEA Advisory Group Meeting on Improved Evaluations and Integral Data Testing for FENDL held in Garching from 12 to 16 September 1994 [3] it was agreed that a new version of the activation library should be prepared within the FENDL-2 Programme. It was decided that the basis will be formed by a sublibrary of important reactions for fusion application [4] complemented with a basic library. Procedures for selection of candidate data and the basic library were defined at that Meeting.

2.1 FENDL/A-2 Sublibrary of Important Reactions

Following the recommendation of the Garching Meeting, the Working Group on Neutron Activation Data initiated an intercomparison of activation cross sections important for fusion reactor technology (ITER project). It was agreed that national nuclear data centres and research laboratories would send to the Nuclear Data Section their contributions, according to a list of selected reactions. Further the rules for submission of candidate data and the selection procedure were set.

A list of 390 important reactions, with assigned priority for the ITER design, that are significant in producing activation both at short and long cooling times was compiled by E. Cheng, R. Forrest, J. Kopecky and F. Mann (see Refs. [4,5]). The list was distributed to all interested parties and in response many activation data were received at the Nuclear Data Section from three major activation libraries (ECN Petten /EAF-4.1/, Obninsk /ADL-3/ and JAERI /JENDL/A-3.2/) and several individual evaluations participated in this exercise. Further, the results of the IAEA Co-ordinated Research Programme on Activation Cross Sections for the Generation of Long-Lived Radionuclides (see INDC(NDS)342) and the 1^st version of FENDL/A1.1 (see IAEA-NDS-148) were considered. Very detailed graphical intercomparisons were prepared at the Nuclear Data Section, plotting, for each reaction, overlays of the various submitted evaluated data sets and experimental data from EXFOR. An international selection panel was formed during the Garching Meeting, with two members from each region. The task of this panel was to make selections of individual important reactions, based on the above graphical intercomparisons and in the later phase to select the basic library.

Panel Members:

Y. Ikeda (Japanese member)

S. Iwasaki (Japanese member)

F. Mann (U.S.A. member)

D. Smith (U.S.A. member)

J. Kopecky (EU member)

H. Vonach (EU member)

A. Ignatyuk (RF member)

V. Manokhin (RF member)

The Selection Panel had two meetings (St. Petersburg - June 1995 [6] and Del Mar - December 1995 [7]) and the rest of the work was carried out via electronic mail. The decisions on the selections for important reactions are shown in Table 1 of Appendix 1.

FENDL/A-2 'important reactions sublibrary' contains pointwise cross section data for the 390 most important reactions for activation studies within the ITER design. The review and selection process was finalized during the assembling of the FENDL/A-2 library in March 1996 at UKAEA Culham and is briefly described below in Section 2.3.

2.2 FENDL/A2 Basic Library

To enable realistic activation calculations to be performed by users the FENDL activation library should be as complete as possible (i.e., containing at least all target nuclides with T(1/2) > 0.5 day and all reactions energetically possible for E_n < 20 MeV). In order to

achieve this in reasonable time, all reaction data from the European Activation File version 4 (EAF-4.1, see Ref. [8]) in pointwise format were selected by the panel to complement the ''important reactions sublibrary'.

2.3 Assembling FENDL/A-2 Library

The task to generate the FENDL/A-2.0 activation and FENDL/D2.0 decay files (March 1996) was performed at UKAEA Fusion by R. Forrest, J.-Ch. Sublet, A. Simpson, J. Kopecky and D. Nierop.

DATA EXTRACTION:

Prior to the assembly of the files, all data were extracted from the latest versions of candidate libraries or individual data sources, as available at UKAEA on March 11 1996, and tested by the processing code SYMPAL-96. They were:

EAF-4.1, ADL-3, FENDL/A-1.1, VONACH (renamed as IRK), CRP (LLRN), ADL-3/I (data received by March 6 from A. Ignatyuk together with CRP) and JENDL/A-3.2 (made available during the night of March 10 to March 11).

IMPORTANT REACTIONS:

The final list of recommended selections from the AGM Del Mar Meeting (INDC(NDS)352) has been used with a few additions:

1. Three reactions have not had any recommendation (noted as 'no plot available'); J. Kopecky looked back into the 'pre-selections' made at the St. Petersburg meeting and made the following choices:

2. For several reactions the selected evaluation has only the total cross section, although, according to the decay data base the branched data are needed. In these cases the EAF branching ratio systematics were applied. Also, if the number of final states (LFS) was not consistent with the EAF data base (such as Pb-204(n,2n)), then the EAF value was adopted. The following reactions and choices had to be treated in this manner:

3. For reactions, where the CRP results have been recommended for one of the partial excitation curves, the complete data set from A. Ignatyuk (March 6 1996) has been included without changes. In some cases he adopted the St. Petersburg recommendations, slightly different from those at Del Mar.

The reactions (obtained from A. Ignatyuk) with their adopted data follow. Since the compilers were not sure whether the ADL-3 data had been slightly adjusted, they call these entries ADL3/I.

¹⁾ Table 1 AGM Del Mar: EAF4.1 for both states

²⁾ The 32y state is assumed as g.s.

³⁾ Table 1 AGM Del Mar: JENDL/A-3.2 for both states

⁴⁾ Table 1 AGM Del Mar: EAF4.1 for g.s. and m1

4. The important reaction Ho-164(n,2n) was not included in the EAF-4.1 library (Ho-164 has T(1/2) < 12 hours). In order to complete the basic library and not to exclude this reaction, the Ho-164 and Ho*164 nuclides have been included in the FENDL/A-2.0 basic data as targets. All the reaction data for these two targets have been adopted from ADL-3.

The sources for the cross section data of important reactions are given in Table 2 of Appendix 1.

PRESENT VERSION OF FENDL/A2.0:

The 'important reactions sublibary' was then merged with the EAF-4.1 library, as available at UKAEA. This is the January 1996 version, which is a slightly improved version that of July 1995, which has been released officially as EAF-4.1. Compilers judged it better to use the latest version, in which some improvements have been made. These mainly concerned formatting errors (some AWT and MAT numbers improved, some interpolation schemes revised); Qvalues are now exclusively taken from the latest version of Moeller data set and finally some (very few) minor data improvements have been included.

The merged version of the important reactions and the EAF-4.1 library has been formally tested at UKAEA Culham with the FISPACT code and was made available to IAEA Nuclear Data Section.

FILES:

The following files were made available to the IAEA Nuclear Data Section:

3. Summary of Contents

The FENDL/A-2 file contains pointwise data for all stable and unstable target nuclides with half-lives longer than 1/2 day. If a reaction produces isomers the cross sections for the ground- and isomer-state are given separately. The FENDL/A-2 includes 739 target nuclides with 13,006 reactions with non-zero cross sections below 20 MeV. The number of reactions included and sources of the data are given in Tables 1 and 2.

Table 1. List of all reaction types included in FENDL/A-2 REACTION TYPE

Table 2. Sources for the cross section data

A list of all reactions with their number of final states, data sources and renormalization comments are given in Appendix 2 (420 KB, PDF).

The following notation is adopted in this list:

              | Origin

                         | RN label

AG*108N,G*    JEF-2.2     RN -/SYS

         | describes the FS (final state)

  | describes the IS (initial state)

IS (Initial State) refers to the target nuclide state e.g IS=-(0) Ground; IS=*(1) First isomer; IS=#(2) Second isomer; FS (Final State) refers to the daughter nuclide state e.g. FS=(0/99) Ground; FS=*(1) First isomer; FS=#(2) Second isomer.

The flag RN displays the information for experimental or systematics renormalisations, at 14.5 MeV, formatted as RN XXX/YYY + text. The first item stands for the total cross section, while the second refers to the isomeric branching (e.g EXP for Experimental or SYS for Systematic).

It should be emphasized that the basic library contains evaluated neutron activation cross sections selected from existing activation data files. In assembling this library, no additional evaluation work was performed in order to improve evaluations; only existing evaluations were considered for inclusion. Therefore, in many cases the data given are theoretical estimates without, or with limited, experimental verification, so that the data uncertainty may be significantly higher than for those evolved from careful evaluation and validation (such as the important reactions).

4. Formats of FENDL/A-2.0

* EAF FORMAT

The format of the EAF-4 file is essentially that of the MF=3 file of ENDF-5 format with the following deviations (see e.g. the EAF-4 final document /ECN-95-072/ for information, the resulting format is usually referred to as the EAF format):

1. Two comment lines have been added in earlier stage: only one is now used stating the origin of data and the EAF revisions. The second one was used earlier to store more detailed information about renormalizations and is now empty.

2. The material number MAT consists of Z and two last digits of A. To describe metastable targets A has been increased by 50 or 70 (m1 or m2, respectively). Consequently, the order of the cross sections (according to increasing MAT numbers) is not always in accordance with increasing Z and A. This applies only to the pointwise format data, not to the multigroup constant library, for which another MAT number with more digits is used.

For example, for stable and m1 metastable target nucleus 67-Ho-166 the material numbers are MAT=6766 and MAT=6816, respectively. For stable and m2 metastable target nucleus 65-Tb-156 the material numbers are MAT=6556 and 6626, respectively. Consequently, the order of the target nuclides (according to increasing MAT numbers) is not always in accordance with the increasing Z and A.

3. The identifiers LIS and LFS are used to indicate the (isomeric) states of the target and final nucleus, respectively. Here we have adopted the convention that LFS = 99 means total production cross section; LFS = I means production of ground state (I = 0), m1 (I = 1) and m2 (I = 2), respectively.

4. The reaction nomenclature is that of ENDF format, except that reaction numbers leading to metastable states have been increased by 300 or 600 (for m1 and m2, respectively). The cross sections for one material number are ordered according to increasing MT numbers, except that cross sections leading to metastable states follow immediately after the cross section leading to the ground state.

Examples of MT numbers are listed below.

MT      Reaction       MT     Reaction

4       (n,n)          304    (n,n)*     1st isomer production

16      (n,2n)         316    (n,2n)*   1st isomer production

                       616    (n,2n)#    2nd isomer production

In order to enable fully automatic retrieval of the history of the previous renormalization procedures and execution of the new renormalization, the composition of the comment line has been recently simplified and only two major items of information are stored:

a. The source of the data adopted is quoted in a format FACTOR*SOURCE (e.g. 1.0000+00*JEF-2.2 means, the data are taken from JEF-2.2 with no renormalization; 8.250001*ENDF/B-VI, the excitation curve has been renormalized to 82.5% of its original value).

b. The flag RN displays the information for experimental or systematics renormalizations, respectively, formatted as RN - XXX/YYY. The first item stands for the total cross section at 14.5 MeV, while the second refers to the isomeric branching (e.g.RN - EXP/SYS means that s_tot has been renormalized to the experiment, while the s_gs and s_m1 have been generated by applying the branching systematics).

* ENDF-6 FORMAT

The EAF-4.1 data also have been converted into pointwise ENDF-6 format with the code ECN-B6I, at IAEA/NDS.

The information of the two comment lines have been placed in the MF=1, MT=451 section.

The material members, reaction nomenclature, and identifiers for isomeric states are the same as in the EAF format.

5. Availability

The files are available from the IAEA Nuclear Data Section online through INTERNET. The file transfer via INTERNET can be performed by FTP command to the address:

IAEAND.IAEA.ORG

The user should login with the user name FENDL2. No password is required. After having logged on the user should go to the subdirectory

[.ACTIVATION.FENDLA]

to see and obtain the following data files:

FENDLA-2.0.liste FENDL-2.0 reactions list

FENDLA-2.0.liste.ps FENDLA-2.0 reactions list in PostScript format

The subdirectory [.ACTIVATION.FENDLA-EAF] contains the FENDL-2.DAT pointwise data file in EAF format. It has a size of 75 Megabytes, i.e. 146265 blocks (1 block = 512 bytes).

Because of its huge size this file was divided into 7 subfiles of a convenient size adequate for FTP transfer:

FENDLA-2.A    Isotopes of 1-H-1         to 32-GE-73

FENDLA-2.B    Isotopes of 32-GE-74      to 44-RU-99

FENDLA-2.C    Isotopes of 44-RU-100     to 52-TE-123

FENDLA-2.D    Isotopes of 52-TE-124     to 60-ND-144

FENDLA-2.E    Isotopes of 60-ND-145     to 71-LU-170

FENDLA-2.F    Isotopes of 71-LU-171     to 83-BI-205

FENDLA-2.G    Isotopes of 83-BI-206     to 94-CM-248

The ENDF-6 version of these pointwise data is available in subdirectory [.ACTIVATION.FENDLA.ENDF] with similar naming: FENDLA-2A.ENDF, FENDLA2B.ENDF, etc.

6. Processing of FENDL/A-2.0

All materials that are represented in the pointwise FENDL/A-2.0 data library were processed in MCNP compatible format and into 175 multigroup VITAMIN-J structure (REAC compatible, LIBOUT and ENDF-6 Formats).

The user should go to the directory

[FENDL2.ACTIVATION.PROCESSED]

to obtain processed working libraries from subsequent subdirectories. These data files are indexed, together with the description of processing, in the IAEA-NDS-174 document, March 1997, "FENDL2/A-MCNP, FENDL2/A-VITJ_E and FENDL2/A-VITJ_FLAT (Ref. 10). The processed FENDL-2 neutron activation cross section data files."

7. FENDL/D-2.0 decay data library

Complementary to the activation cross section library is the ENDF-6 formatted decay data library supplied to Nuclear Data Section by R.A. Forrest. The library is taken directly from the decay data library used in the European Activation System (EASY) version 4.1 [9]. The choice was made so that the identification of daughter nuclides in the decay library is compatible with the cross section library since the majority of the reactions in FENDL/A-2.0 is equivalent to the cross section library EAF-4.1. No changes have been made to the FENDL/D2.0 library so that it is identical to the EAF-4.1 decay library. Due to the inclusion of the important reactions sub-file, there will be a few cases in which inconsistency of isomeric states between the two libraries remain.

FENDL/D2.0 contains decay properties (decay type, decay energy, half-life) for 1867 nuclides and isomers.

The format of this decay library is largely in ENDF-6: MF=8, MT=457 format. In an effort to include identifying information on the stable nuclides required for activation calculations, entries are included in ENDF-6 MF=1, MT=451 format for these nuclides. It is noted that for a few nuclides the entry is in ENDF-5 format, with one fewer line in the MT=451 section.

FILESETS:

FENDL/D-2.0 decay data library is available in the Nuclear Data Section open area ''FENDL2" under the subdirectory

[.DECAY.FENDLD]

It has a size of 30 Megabytes.

The data are split into 10 subfiles to aid handling, covering the particular groups of nuclides shown below.

FENDLD_2.001     ¹H - ⁸⁶Br

FENDLD_2.002     ⁷⁴K - ¹¹¹Ru

FENDLD_2.003     ⁹⁶Rh - ^131mSn

FENDLD_2.004     ¹¹²Sb - ¹⁴⁰Cs

FENDLD_2.005     ¹²⁴Ba - ¹⁶⁰Eu

FENDLD_2.006     ¹⁴⁵Gd - ¹⁷⁶Tm

FENDLD_2.007     ¹⁶²Yb - ¹⁹⁵Re

FENDLD_2.008     ¹⁸⁰Os - ²¹⁰Tl

FENDLD_2.009     ¹⁹⁵Pb - ²³⁴Ac

FENDLD_2.010     ²²⁴Th - ²⁴⁸Cm

See also AAREADME.TXT file in the directory for further information.

All materials that are presented in the FENDL/D-2.0 decay library were processed into REAC compatible format by F.M. Mann, Hanford, Westinghouse, U.S.A. The data are available in the subdirectory

[.DECAY.FENDLD.REAC]

The REAC formatted data are grouped into 21 bins.

References:

[1] Proceedings of the IAEA Specialists' Meeting on Fusion Evaluated Nuclear Data Library (FENDL), Vienna, 8-11 May 1989, Report INDC(NDS)-223, August 1989, prepared by V. Goulo

[2] A.B. Pashchenko and P.K. McLaughlin, FENDL/A-1.1 - Neutron Activation Cross Section Data Library for Fusion Applications, Version 1.1 of April 1993, Report INDC(NDS)-148, February 1995

[3] Summary report of the IAEA Advisory Group Meeting on 'Improved Evaluations and Integral Data Testing for FENDL', Garching, 12-16 September 1994, Report INDC(NDS)-312, December 1994, prepared by S. Ganesan

[4] E.T. Cheng, R.A. Forrest, J. Kopecky and F.M. Mann, List of Neutron Activation Reactions Important for Fusion Power Plant Technology, EAF-Doc-004 (March 1994)

[5] Summary report of the IAEA Specialists' Meeting on 'Comparison of Activation Cross Section Measurements and Experimental Techniques for Fusion Reactor Technology', Tokai, 15-17 November 1993, Report INDC(NDS)-301, July 1994, prepared by A.B. Pashchenko

[6] IAEA Consultants' Meeting on 'Selection of Evaluations for the FENDL/A-2 Activation Cross Sections Library', St. Petersburg, 25-27 June 1995, Report INDC(NDS)-341, February 1996, prepared by A.B. Pashchenko

[7] Summary report of the IAEA Advisory Meeting on 'Completion of FENDL-1 and start of FENDL-2', Del Mar, 5-9 December 1995, Report INDC(NDS)-352, March 1996, prepared by A.B. Pashchenko.

[8] J. Kopecky and D. Nierop, The European Activation File EAF-4 - Summary Documentation, ECN-C-95-072, December 1995

[9] R.A. Forrest and J.-Ch. Sublet, FISPACT 4 User Manual, UKAEA Report, UKAEA FUS 287, 1995

10) A.B. Pashchenko and H. Wienke, 'FENDL2/A-MCNP, FENDL2/A-VITJ_E and FENDL2/A-VITJ_FLAT, the processed FENDL-2 neutron activation cross section data files', report IAEA(NDS)-174, Rev. 0 (International Atomic Energy Agency, March 1997).

Appendix 1

LIST OF ACTIVATION REACTIONS IMPORTANT FOR

FUSION APPLICATIONS

Table 1. Results of selections reached (final date - March 1996)

Notes:

1. Under the column Reaction: the sum of cross sections forming all isomeric states is indicated. If particular isomeric products are required these are shown by: g-ground state, m-1st isomer, n-2nd isomer.

2. Under the column T1/2: the daughter nuclide with the half-life of the target is given.

3. Under the column Priority: the priority of the reaction for the ITER design calculations is quoted, as deduced in Refs. [4,5].

4. Under the column Selected candidate: the source of data is given:

- IRK stands for evalution originating from the Institut fr Radiumforschung und Kernphysik Vienna;

- CRP is a product of the Research Coordination Programme on the Activation Cross Sections for the Generation of Long-lived Radionuclides of IAEA [see INDC(NDS)342];

- The rest of selections come from well known and released libraries.

Table 2. The sources for the cross section data of important reactions

Attachment

DISTRIBUTION OF THE FENDL-2 LIBRARY

(As recommended at the IAEA Advisory Group Meeting on FENDL,

held at IAEA Headquarters, Vienna, Austria, March 1997.)

The master copy of the FENDL-2 library resides with the Nuclear Data Section of the International Atomic Energy Agency. To facilitate user access to the library the official copy of FENDL-2 will be distributed to the major nuclear data centres in Europe (NEA Data Bank, Paris), Japan (JNDC, Tokai-mura), Russia (CJD,Obninsk) and USA (NNDC, Brookhaven and RSIC, Oak Ridge). As agreed between data centers, sharing common FENDL information, the recipients are receiving now the same products from all above centers. The data are available and may be further distributed to the user community according to the customer service options given below. Each FENDL sub-library will be in a single data set, i.e. Activation, Decay, etc. in the 8 mm tape, 6 mm tape, 4 mm tape or standard 9 track magnetic tape (6250 bpi or 1600 bpi) and CD-ROM options. The interested scientists may request FENDL-2 (or parts of it) directly from the IAEA/NDS or from one of these centers.

FENDL CUSTOMER SERVICE OPTIONS

Table notes

1) NNDC will distribute FENDL unprocessed data
2) RSIC will distribute FENDL processed data
3) RSIC offers cost free service to ITER customers