RSIC COMPUTER CODE PSR-033

1. NAME AND TITLE

GAROL: Calculation of Resonance Neutron Absorption in Two-Region Problems.

2. CONTRIBUTOR

General Atomic, San Diego, California, through the Argonne Code Center, Argonne, Illinois.

3. CODING LANGUAGE AND COMPUTER

Fortran IV; IBM 7090.

4. NATURE OF PROBLEM SOLVED

GAROL studies resonance absorption and can handle overlap effects between resonances of a resonance absorber and of mixtures of resonance absorbers.

5. METHOD OF SOLUTION

One of the assumptions which has been included in most treatments of resonance absorption is that, in a mixture of resonance absorbers, the total absorption may be obtained by summing the absorptions in each resonance of each nuclide, each being computed as if the other resonances were not present. GAROL does not make this assumption; it explicitly takes into account those effects which arise from resonance overlap of an individual resonance absorber and of mixtures of different resonance absorbers. It is conventional to consider the problem as a lattice of absorber imbedded in a purely scattering medium in which the flux is taken to be 1/E. Thus, the flux dips in the scattering medium due to absorptions in the lump are neglected. For tight lattices, this approximation can be poor. GAROL does not make this assumption; it solves two coupled integral equations for the fluxes in each region.

6. RESTRICTIONS OR LIMITATIONS

None noted.

7. TYPICAL RUNNING TIME

No study has been made by RSIC of typical running times for GAROL. Generally speaking, the computer time is greatest for lighter materials. The only exception is for A=1.0 which is fastest of all because it is programmed differently.

8. COMPUTER HARDWARE REQUIREMENTS

GAROL is operable on the IBM 7090 computer.

9. COMPUTER SOFTWARE REQUIREMENTS

A Fortran IV compiler is required.

10. REFERENCES

C. A. Stevens and C. V. Smith, "GAROL: A Computer Program for Evaluating Resonance Absorption Including Resonance Overlap," GA-6637 (August 24, 1965).

G. P. Lahti and R. M. Westfall, "Multigroup Resonance-Region Cross Sections for Tungsten and Depleted Uranium for Use in Shielding Calculations," NASA TM X-1909 (January 1970).

11. CONTENTS OF CODE PACKAGE

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

12. DATE OF ABSTRACT

November 1983.

KEYWORDS: MULTIGROUP CROSS SECTION PROCESSING; NEUTRON CROSS SECTION PROCESSING