RSIC COMPUTER CODE PSR-080

1. NAME AND TITLE

FATDUD: Foil Activation Data Unfolding Code System.

AUXILIARY ROUTINES

GRAPH: Plotting Program.

PLOTER: Plotting Program.

XSECTION: Cross Section Library Preparation.

2. CONTRIBUTOR

Breazeale Nuclear Reactor Center, The Pennsylvania State University, University Park, Pennsylvania.

3. CODING LANGUAGE AND COMPUTER

Fortran IV, Assembler Language; IBM 360/370.

4. NATURE OF PROBLEM SOLVED

FATDUD unfolds neutron spectra or cross sections from reaction rate data expressed as activation/atom-sec.

5. METHOD OF SOLUTION

The unfolding method used by FATDUD is based on an iterative technique developed by R. E. Fortney and S. H. Levine. FATDUD refers to this as the F-L technique. This iterative method converges rapidly (usually after 30 to 60 iterations), the solution is almost entirely independent of the starting guess, and any oscillations which develop are heavily damped.

6. RESTRICTIONS OR LIMITATIONS

None noted.

7. TYPICAL RUNNING TIME

No study has been made by RSIC of typical running times for FATDUD.

8. COMPUTER HARDWARE REQUIREMENTS

FATDUD is operable on the IBM 360/370 computers. If all options are in use it requires 280 K bytes of core on an IBM 370/168 computer.

9. COMPUTER SOFTWARE REQUIREMENTS

A Fortran IV H-level compiler is required.

10. REFERENCE

J. K. Schmotzer, "User's Package for FATDUD Foil Activation Data Unfolding," PSBR 315-497485.

11. CONTENTS OF CODE PACKAGE

Included are the referenced document and one (1.2MB) DOS diskette which contains the source code and sample problem input and output, and library routines.

12. DATE OF ABSTRACT

February 1984.