BNL-NCS-50496 (ENDF 102) (General Reactor Technology - T10-4500) ENDF-102 DATA FORMATS AND PROCEDURES FOR THE EVALUATED NUCLEAR DATA FILE, ENDF Revised by D. GARBER, C. DUNFORD, AND S. FEARLSTEIN October 1975 This publication brings under one cover what was formerly Vol. I (neutron formats) and Vol. II (photon formats) tf miitm*- til ^ »otic» :'^lH^-:1ra<y gggf.IOHS_QP THIS REPORT ARE ILLEGIBLE. It ""• ' hns been reproduced from the hest available copy to p*rmit %h* broadest possible avail- , ability. INFORMATION ANALYSIS CENTER REPORT NATIONAL NEUTRON CROSS SECTION CENTER BROOKHAVEN NATIONAL LABORATORY ASSOCIATED UNIVERSITIES, INC. UPTON, NEW YORK 11973 UNDER CONTRACT NO. E(3O-1)-16 WITH THE UNITED STATES ENERGY RESEARCH AND DEVELOPMENT ADMINISTRATION This publication is based on previous reports: BNL 838], ENOF - Evaluoted Nuclear Data File Description and Specifications, June 1964, H.C. Honeck. BNL 50066, ENDF 102, Vol. I - ENDF/8 - Specifications for an Evaluated Nuclear Data File for Reactor Applications, May 1966, H.C. Honeck; Rev. July 1967, S. Pearlstein; Rev. Oct. 1970, M.K. Drake, Editor. LA 4549, ENDF 102, Vol II - ENDF Formats and Procedures for Photon Production and Interaction Data, Oct. 1970, DJ. Dudziak. It brings under one cover both the neutron and photon formats. NOTICE This report was prepared as an account of work sponsored by the United States Government. Neither the United States nor the United States Energy Research and Development Administration, nor any of their employees, nor any of their contractors, subcontractors, or their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness or usefulness of any information, apparatus, product or process disclosed, or represents that its use would not infringe privately owned lights. Printed in the United States of America Available from National Technical Information Service U.S. Department of Commerce 5285 Port Royal Road Springfield, VA 22161 Price: Domestic $i**jr; Foreign SI5.25; Microfiche S2.25 March 1976 _ 500 copies - iii - DATA FORMATS AND PROCEDURES FOR THH ENDF NEUTRON CROSS SECTION LIBRARY 0. ENDF/B-IV VERSION PREFACE 0.1. INTRODUCTION 0.2. GENERAL FEATURES OF THE EVALUATED NUCLEAR DATA FILE 0.3. FELATIONSHIP OF THE ENDF TO OTHER PAIR SYSTEMS 0.3.1 Experimental Data Libraries 0.3.2 Processing Codes and Neutronics Calculations 0.4. GENERAL, DESCRIPTION OF THE ENDF LIBRARY 0.4.1 Definitions and Conventions 0.4.2 Structure of an ENDF Data Tape 0.4.3 Representation of Data 0.5. GENERAL DESCRIPTION OF THE DATA FORMATS 0.5.1 Nomenclature 0.5.2 Types of Binary Records 0.5.3 Card Image (BCD) Format 1. FILE 1, GENERAL INFORMATION 1.1 Descriptive Data and Dictionary (MT = 451) 1.1.1 Formats 1.1.2 Procedures 1.2 Number of Neutrons per Fission, v (MT = 452) 1.2.1 Forma ts 1.2.2 Procedures 1.3 Radioactive Nuclide Production (MT = 453) 1.3.1 Formats 1.3.2 Procedures - iv - DATA FORMATS AND PROCEDURES 1.4 Fission Product Yield Data (MT = 4 54) 1.4.1 Formats 1.4.2 Procedures 1.5 Delayed Neutron Data, v (MT = 455) 1.5.1 Formats 1.5.2 Procedures 1.6 Nuirber of Prompt Neutrons per Fission, v (MT = 456) 1.6.1 Formats 1.6.2 Procedures 1.7 Radioactive Decay Data (MT = 457) 1.7.1 Formats 1.7.2 Procedures 2. FILE 2, RESONANCE PARAMETERS 2.1 General Description 2.2 Resolved Resonance Parameters 2.2.1 Formats 2.2.2 Procedures 2.3 Unresolved Resonance Parameters 2.3.1 Formats 2.3.2 Procedures 3. FILE 3, NEUTRON CROSS SECTIONS 3.1 General Description 3.2 Formats 3.3 Procedures - v - DATA FORMATS AND PROCEDURES 4. FILE 4, ANGULAR DISTRIBUTIONS OF SECONDARY NEUTRONS 4.1 General Description 4.2 Formats 4.3 Procedures 5. FILE 5, ENERGY DISTRIBUTIONS OF SECONDARY NEUTRONS 5.1 General Description 5.2 Representation of Energy Distributions 5.3 Formats 5.4 Procedures 6. FILE 6, ENERGY-ANGULAR DISTRIBUTIONS FOR SECONDARY NEUTRONS 6.1 General Description 6.2 Formats 6.3 Procedures 7. FILE 7, THERMAL NEUTRON SCATTERING LAW DATA 7.1 General Description 7.2 Formats 7.3 Procedures 11. GENERAL COMMENTS ON PHOTON PRODUCTION 12. FILE 12, PHOTON PRODUCTION MULTIPLICITIES AND.TRANSITION PROBABILITY ARRAYS 12.1 Formats 12.1.1 Option 1 (L0=1): Multiplicities 12.1.2 Option 2 (L0=2): Transition Probability Arrays 12.2 Procedures - vi - DATA FORMATS AND PROCEDURES 13. FILE 13, PHOTON PRODUCTION CROSS SECTIONS 13.1 Formats 13.2 Procedures 13.3 Preferred Representations 14• FILE 14, PHOTON ANGULAR DISTRIBUTIONS 14.1 Formats 14.2 Procedures 15. FILE 15, CONTINUOUS PHOTON ENERGY SPECTRA 15.1 Formats 15.2 Procedures 16. FILE 16, PHOTON ENERGY-ANGLE DISTRIBUTIONS 16.1 Formats 16.2 Procedures 2 2. GENERAL COMMENTS ON PHOTON INTERACTION 23. FILE 23, "SMOOTH" PHOTON INTERACTION CROSS SECTIONS 23.1 Formats 23.2 Procedures 24. FILE 2Ar SECONDARY ANGULAR DISTRIBUTIONS FOR PHOTON INTERACTION 24.1 Formats 25. FILE 25, SECONDARY ENERGY DISTRIBUTIONS 26. FILE 26, SECONDARY ENERGY-ANGLE DISTRIBUTIONS 27• FILE 27, ATOMIC FORM FACTORS OR SCATTERING FUNCTIONS 27.1 Formats 27.2 Procedures - vii - APPENDIX A: Glossary B: Definition of Reaction Types C: ZA Designation of Materials D: Resonance Region Formulae E: Interpolation Schemes F: Temperature Dependence G: Alternative Structure for EHDF Data Tapes H: Data Formats for the ENDF/A Library I: Summary of Processing Codes Used with the ENDF Library J: Materials in the ENDF/B Library K: Sample Data Set L: Sample of Interpreted Data Set M: Sample Graphical Display N: Examples of Card Image Formats 0: Format Differences Between Versions of the ENDF Library P: Summary of Important ENDF Rules Q: Dimensions of Important ENDF Parameters R: Trial Format for Non-Neutron Data - viii - 0. ENDF/B - IV PREFACE These revisions to Data Formats and Procedures for the ENDF Neutron Cross Section Library, ENDF-102, pertain to the latest "er .ion of ENDF/B-IV. The descriptions of the formats have been brought up to date and important proce- dural matters have been explained. Other explanations of formats will be made at a later time. Users of this manual who note deficiencies or have suggestions arc encouraged to contact the National Neutron Cross Section Center at Brook- haven National Laboratory. Three new appendices have been added. Appendix P contains a checklist of the most important rules for or misunderstandings about ENDF formats and proce- dures. Appendix Q summarizes the dimensions of important ENDF variables. Ap- pendix R describes a new trial format approved for Files 62-76 that is now be- ing tested for non-neutron reaction data. Some of the data in the 1974 version of ENDF/B will contain files of data variances, sometimes called error files. Formats and procedures for the error files will be supplied at a later date. The authors have been helped in these revisions by several people. Much material is based on an April 1973 draft memo entitled "Clarification of Exist- ing Formats and Procedures" by M. K. Drake. The formats for radioactive decay data were largely constructed, clarified, and implemented by 0. Ozer, C. W. Reich, and R. E. Schenter. Numerous people, in the U.S. ard abroad, submitted suggestions and ideas, many of which were included in this edition. - 0.1 - 1. IJJTKUJDUCTIUN 0.1.1. ENDF System This report describes the philosophy, of the Evaluated Nuclear Data File (ENDF) * and the data formats and procedures that have been developed for it. The ENDF system was designed for the storage and retrieval of the evaluated nuclear data that are required for neutronics, photonics and decay heat calcu- lations. This system is composed of several parts that include a series of data processing codes and neutron and photon cross section nuclear structure libraries. The ENDF system was developed to provide a unified format that could be used to store and retrieve evaluated sets of neutron cross sections. It was designed to allow easy exchange of cross section information between various laboratories. The initial systom contained format specifications for neutron cross sections and other related nuclear constants. During the later stages of development the formats were expanded to include photon interaction cross sections, photf.n production data (photons produced by neutron interactions) and nuclear structure data. The basic data formats developed for the library are versatile enough to allow accurate description of the cross sections considered foi a wide range of incident neutron energies (10 " eV to 20 MeV). The ENDF formats are flexi- ble in the sense that almost any type of neutron interaction mechanism can be accurately described. They are restrictive in that only a limited number of different representations are allowed for any given neutron reaction mechanism. *This report supersedes the descriptions of the ENDF/B library given in BNL 8381 and in BNL 50066 (ENDF 102). - 0.2 - V1.2. KNDF Documentation The purpose of this report is to describe the data formats and tht> pro- cedures to be used for entering data into the L'NDF library. In addition, this report describes the relationship between the ENDF evaluated data libraries and the experimental data library CSISRS (Cross Section information Storage and Retrieval System). The relationship between the ENDF libraries and the processing codes that are used to generate secondary data libraries (for exam- ple, fine group-averaged cross section libraries) is also described. The pro- cessing codes connected with the ENDF libraries are summarized here, but the codes themselves are described in separate documents. This report is organized in the following manner. The first section de- scribes the general features of the ENDF libraries, the relationship between ENDF and CSISRS, and the relationship between ENDF and its secondary libraries.