Argonne National Laboratory

Nuclear Science and Engineering

ETOE-2

A program for ENDF/B to MC2-3 data conversion

Standard Code Description

  1. Coding Language and Computing Platforms
    Fortran source code for Linux
  2. Description of Purpose
    ETOE-2 accepts cross-section data from an ENDF/B version 5 through 7 library tape in binary alternate form and prepares the cross section libraries for the MC2 processing code. The MC2 data library generated consists of eight files containing (1) the administrative file; (2) function table file; (3) unresolved resonance data; (4) resolved resonance data; (5) smooth tabulated non-resonant data; (6) inelastic and (n, 2n) distributions; (7) fission spectra data; and (8) Legendre data.

    The ETOE code accepts the ENDF/B version 5 to 7 formats which permit a large number of options in describing the fundamental data. Many of these options have not been used in the past versions of ENDF/B data, and only a subset of the allowed ENDF/B specifications can be processed by MC2 directly without modifications. The code provides the means to convert various ENDF/B data into the form or energy structure readily amenable to MC2. For example, the MC2 resolved resonance algorithms assume either a single or multilevel Breit-Wigner or a multilevel Adler-Adler format. The ENDF/B-6 format also permits R-Matrix (Reich-Moore) parameters which ETOE-2 converts to multipole parameters (Ref. 1) that preserve the general features required by the traditional resonance integral concept and the Doppler-broadening algorithm in MC2 without compromising rigor. Similarly, ENDF/B permits six secondary energy distribution laws for inelastic and (n, 2n) scattering, whereas MC2 permits only three. The ETOE code generates tabular data if the ENDF/B data employ any of the three laws not processed by MC2. Similar examples may be cited in the processing of elastic scattering distributions and fission spectrum data. In general, the format conversions performed by ETOE do not alter the basic data provided on the ENDF/B files.

    The ETOE-2 program thus provides an automated capability for the generation of MC2 library files from ENDF/B data. Currently the ultra-fine-group (ufg) energy structure chosen to form the MC2 libraries is 2082 groups with constant lethergy (1/120) from 15 MeV to .4 eV. Since ETOE is variably dimensioned, any number of ufg lethargy intervals is possible. ETOE generates ufg data for all the ENDF/B representations except resolved and unresolved data and fission spectra data. Since the library files generated by ETOE are not composition dependent, the program only needs to be executed when new fundamental data become available (e.g., each release of ENDF/B).

    At user option, the ETOE-2 code calculates resonance cross sections from ENDF/B resonance parameters for all materials of mass less than an input value. Generally, a mass of 100 is used. These ​“light” element resonance cross sections are then combined with the ENDF/B ​“floor” cross sections and integrated over ultra-fine-group energy boundaries (u = 1/120) to provide the group cross sections required by MC22/SDX. It is assumed that ​“light” element resonance cross sections are composition-independent on the ultra-fine-group level.

    ETOE-2 prepares MC2 binary libraries using a binary alternate form ENDF/B library tape. RIGEL (NESC Abstract 915) can be used to create the ENDF/B binary alternate tape.
  3. Typical Running Time
    The run time is irrelevant on modern computing machines due to their speed and the frequency that ETOE is executed on new releases of ENDF/B.
  4. References
    1. R. N. Hwang, ​“A Rigorous Pole Representation of Multilevel Cross Sections and Its Practical Applications,” Nuclear Science and Engineering, 96, pp. 192-209, April 1987.
    2. C. G. Stenberg and R. N. Hill, ​“Addition of the MC22 Libraries and Updates to the MC22 Code on the RA Workstations (#5),” Argonne National Laboratory Internal Memorandum, August 10, 1993.
    3. ETOE-2, NESC No. 350 ETOE-2 Documentation, National Energy Software Center Note 83-84, August 25, 1983.
    4. H. Henryson, II, B. J. Toppel, and C. G. Stenberg, ​“MC2-2: A Code to Calculate Fast Neutron Spectra and Multigroup Cross Sections,” ANL-8144, June 1976.
    5. R. Kinsey, ​“Data Formats and Procedures for the Evaluated Nuclear Data File, ENDF,” BNL-NCS-50496 (ENDF-102), second edition (ENDF/B-V), October 1979.
    6. Odelli Ozer, Ed., ​“Description of the ENDF/B Processing Codes and Retrieval Subroutines,” BNL 50300 (ENDF-110), September 1967, revised June 1971.
    7. D. M. Green and T. A. Pitterle, ​“ETOE, A Program for ENDF/B to MC2 Data Conversion,” APDA-219 (ENDF-120), June 1968.
  5. Materials Available
    The source code and compilation instructions are provided. Precompiled executables for Linux and Macintosh are available. Documentation on methodology and installation is provided along with all of the verification test cases. Contact nera-​software@​anl.​gov for licensing and distribution information.
  6. Primary Authors
    • C. G. Stenberg, Nuclear Engineering Division, Argonne National Laboratory
    • C. H. Lee, Nuclear Science & Engineering Division, Argonne National Laboratory
  7. Sponsor
    U.S. Department of Energy, Office of Nuclear Energy