1. NAME AND TITLE

GFX-GAMIX: A Spherical Harmonics Code System for Evaluation of Terrestrial Gamma-Radiation Fields.

2. CONTRIBUTOR

Riso National Laboratory, Roskilde, Denmark through the OECD NEA Data Bank, Gif-sur-Yvette, France.

3. CODING LANGUAGE AND COMPUTER

Fortran IV, Assembler language; IBM 3033.

4. NATURE OF PROBLEM SOLVED

GFX-GAMIX is a computer code for the evaluation of terrestrial gamma-radiation fields, i.e., environmental radiation fields produced by the natural gamma-ray emitters (⁴⁰K and members of the thorium and the uranium decay series) in the ground. It is intended as an aid to the interpretation of ground and airborne gamma-ray surveys.

5. METHOD OF SOLUTION

The code is a consistent data-processing system for the solution of the one-dimensional, plane, two-media photon transport equation. The programs use efficient numerical techniques, and the data files are kept on random-access disk-pack storage. The solution method is the double-P₁ (DP1) approximation with logarithmic energy spacing. The complete data-processing system GB contains the transport-theory code GAMP1, the code GFX for computation of scalar flux and dose rate, and a number of auxiliary programs and data files.

6. RESTRICTIONS OR LIMITATIONS

None noted.

7. TYPICAL RUNNING TIME

No study has been made by RSIC of typical running times for GFX-GAMIX.

8. COMPUTER HARDWARE REQUIREMENTS

The code is operable on the IBM 370/3033 computer.

9. COMPUTER SOFTWARE REQUIREMENTS

A Fortran IV compiler is required.

10. REFERENCE

P. Kirkegaard and L. Lovborg, "Program System for Computation of the Terrestrial Gamma-Radiation Field," Riso-R-392 (February 1979).

11. CONTENTS OF CODE PACKAGE

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

12. DATE OF ABSTRACT

February 1982.