1. NAME AND TITLE

CYGAS: A Gamma-Ray Attenuation Code System for Large Gamma-Ray Sources Shielded by Coaxial Cylinders.

2. CONTRIBUTOR

Kjeller Computer Installation, Kjeller, Norway, through the NEA OECD Data Bank, Gif-sur-Yvette, France.

3. CODING LANGUAGE AND COMPUTER

FORTRAN IV; IBM 360/370.

4. NATURE OF PROBLEM SOLVED

CYGAS computes the gamma-ray flux and dose in three-dimensional geometry around a cylindrical source of finite height shielded by coaxial infinite cylindrical shields in the radial direction and slab shields in the axial direction.

5. METHOD OF SOLUTION

The axial flux at each specified dosepoint is determined by integration of the disk source attenuation kernel with the Taylor buildup factor for a plane source. The radial flux at each dose point, specified by R-Z coordinates, is calculated by integration of the line source kernel with the Taylor buildup factor.

6. RESTRICTIONS OR LIMITATIONS

The program handles 50 regions of different materials and 10 different buildup factors.

7. TYPICAL RUNNING TIME

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

8. COMPUTER HARDWARE REQUIREMENTS

CYGAS is operable on the IBM 360/370. It requires 32 K of storage.

9. COMPUTER SOFTWARE REQUIREMENTS

A FORTRAN IV compiler is required.

10. REFERENCE

T. O. Sauer, "CYGAS, An Attenuation Code for Large Cylindrical Gamma Sources with Multilayer Shields."

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

December 1981.