IAEA0854 SIGMA1-2007.

1. NAME OR DESIGNATION OF PROGRAM:  SIGMA1-2007.

3. DESCRIPTION OF PROBLEM OR FUNCTION

SIGMA-1 Doppler broadens evaluated cross sections given in the linear-linear interpolation form of the ENDF/B format to one final temperature. The data is Doppler broadened, thinned, and output in the ENDF/B format.

This version include the updates up to JANUARY 30, 2007.
Changes in ENDF/B-VII Format and procedures, as well as the evaluations themselves, make it impossible for versions of the ENDF/B pre-processing codes earlier than PREPRO 2007 (2007 Version) to accurately process current ENDF/B-VII evaluations.
The present code can handle all existing ENDF/B-VI evaluations through release 8, which will be the last release of ENDF/B-VI.
  
MODIFICATIONS FROM PREVIOUS VERSIONS:
-------------------------------------
Sigma-1 VERS. 2007-1 (JAN. 2007): checked against all ENDF/B-VII; increased page size from 60,000 to 360,000 energy points

4. METHOD OF SOLUTION

The energy grid is selected to ensure that the  broadened data is linear-linear interpolable. SIGMA-1 starts from the free-atom Doppler broadening equations and adds the assumptions  of linear data within the table and constant data outside the range  of the table. If the original data is not at zero Kelvin, the data is broadened by the effective temperature difference to the final temperature. If the data is already at a temperature higher than the final temperature, Doppler broadening is not performed.

5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM

The input to SIGMA-1 must be data which vary linearly in energy and cross section between tabulated points. The LINEAR program provides such data. LINEAR uses only the ENDF/B BCD format tape and copies all sections except  File 3 as read. Since File 3 data are in identical format for ENDF/B Versions I through VI, the program can be used with all these versions. - The present version Doppler broadens only to one final temperature.

6. TYPICAL RUNNING TIME:  A few seconds.

7. UNUSUAL FEATURES OF THE PROGRAM

The allowable error may be energy dependent or independent (constant). The allowable energy
dependent error is described by a tabulated function of up to 20 (energy,error) pairs.

8. RELATED AND AUXILIARY PROGRAMS

The following programs are all part of the PREPRO2002 package.  
ACTIVATE: is designed to create file 10 activation cross sections by
          combining file 3 cross sections and file 9 multipliers
COMPLOT: Compares ENDF/B formatted data from two separate input
         files. Results are in graphical form.  
CONVERT: Automatically converts a FORTRAN program for use on
         any one of a variety of: (1) computers; (2) compilers:
         (3) precisions; (4) installations; (5) standard or
         non-standard file names.  
DICTIN:  Creates a reaction index for each material.  
EVALPLOT:Plots data in the ENDF/B format.  
FIXUP:   Reads evaluated data in the ENDF/B format; performs
         corrections and outputs the results in the ENDF/B format.  
GROUPIE: calculates unshielded group averaged cross sections,  
         Bondarenko self-shielded group averaged cross sections,
         and multiband parameters from data in the ENDF/B format.  
LEGEND:  Calculates linearly interpolable tabulated angular  
         distributions starting from data in the ENDF/B format.  
LINEAR:  Converts cross sections in the ENDF/B format (File 3,
         23, and 27) to linearly interpolable form (in energy  
         and cross section) and outputs the result in the ENDF/B
         format.  
MERGER:  Selectively retrieves data by MAT/MF/MT or ZA/MF/MT from
         up to 10 ENDF/B data tapes and merges the data into a
         single MAT/MF/MT ordered output file.  
MIXER:   Calculates the energy dependent cross sections for a
         composite mixture.  
RECENT:  Reconstructs energy-dependent cross sections from a
         combination of resonance parameters and tabulated  
         background cross sections in the ENDF/B format.  
RELABEL: relabels a ENDF/B preprocessing program so that  
         statement labels are in increasing order in increments of
         10 within each routine.  
SIGMA-1: Doppler broa
dens evaluated cross sections in the
         linear-linear interpolation form of the ENDF/B format.
SIXPAK:  Checks all double-differential ENDF/B-VI format data  
         (MF=6) and outputs equivalent uncorrelated data (MF=4,
         5, 12, 14, and 15)  
VIRGIN:  Calculates uncollided flux and reactions due to
         transmission of a monodirectional beam of neutrons
         through any thickness of material.

10. REFERENCES:

- IAEA Nuclear Data Section:
PREPRO2007, 2007 ENDF/B Pre-processing Codes (ENDF/B-VII Tested)
IAEA-NDS-39, Rev. 13, March 17, 2007

11. MACHINE REQUIREMENTS

The package is designed to be used with many machines. Make files for almost all kind of computers are included.

13. OPERATING SYSTEM UNDER WHICH PROGRAM IS EXECUTED:  Several OS can be used.

14. OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS:

15. NAME AND ESTABLISHMENT OF AUTHOR

Nuclear Data Section
IAEA
P.O. Box 100
A-1400 VIENNA
AUSTRIA

General description of the PrePro2007 programs
Documentation
Compressed files for MAC, Readme file for MAC
Author's Make file for PCLinux, Author's LINUX executable
Author's PCWindows compile batch
Author's PCWindows executable
Fortran source files for different platfor
UNIX Makefiles for different platforms
Author's VMS executable, Author's compile command file