1. NAME AND TITLE
G3-6ED: Kernel Integration Code System Multigroup Gamma Ray Scattering.
The original version of G3-6ED (G cubed 6th edition), written at LASL, was known as GAS. With usage, revisions and name changes to the code package have been given by RSIC contributors since early 1966. Major contributions were made to the code system by NASA Lewis Research Center, Cleveland, Ohio, and Aerojet-General Nucleonics, San Ramon, California. The current CDC version resulted from a full review and update made by LASL in 1973. The IBM version of this later package was contributed by Southern Services in 1975.
2. CONTRIBUTORS
Los Alamos Scientific Laboratory, Los Alamos, New Mexico.
NASA Lewis Research Center, Cleveland, Ohio.
Aerojet-General Nucleonics, San Ramon, California.
Southern Services, Inc., Atlanta, Georgia.
Radiation Research Associates, Ft. Worth, Texas.
3. CODING LANGUAGE AND COMPUTER
FORTRAN IV; CDC 6600 (A), IBM 360/370/195 (B), and PERKIN ELMER 3220.
4. NATURE OF PROBLEM SOLVED
The General Geometry Gas (GGG or G3), sixth edition (6ED) enables the user to estimate gamma-ray scattering from a point source to a series of point detectors. The output includes detector response due to each source energy, as well as a grouping by scattered energy in addition to a simple, direct beam result. Although G3-6ED is basically a single-scatter program, it also includes a correction for multiple scattering by applying a buildup factor for the path segment between the point of scatter and the detector point. Results are recorded with and without the buildup factor. Surfaces, defined by quadratic equations, are used to provide for a full three-dimensional description of the physical geometry. It evaluates scattering effects in those situations where more exact techniques are not economical.
5. METHOD OF SOLUTION
An orthogonal scattering geometry specification is superimposed on the general CCC-48/QAD geometry; the midpoint of the orthogonal cube is ascertained, the QAD region in which this point is located is determined, and the entire scatter volume is assumed to be of the ascertained QAD material and concentrated at the mid-point. G3-6ED traces a ray from the source point to each scatter point, calculates uncollided photon flux at that point, and (from the Klein-Nishina differential cross-section and knowledge of the electron density at the scatter point) determines contribution from each scatter point to the detector. The library of photon cross sections and buildup factors used is the same as that used by QAD-HD (NASA-TM-X-1397).
6. RESTRICTIONS OR LIMITATIONS
The following limits apply: 20 x 20 x 20 scatter grid, 50 QAD boundaries and regions, and 30 energy groups.
7. TYPICAL RUNNING TIME
No study has been made by RSIC.
8. COMPUTER HARDWARE REQUIREMENTS
The codes may be run on computers with at least 32 K of memory.
Two peripheral storage devices (tape units or disks) are used. The packaged versions are operable on CDC 6000 and IBM 360/370 series computers and PERKIN ELMER 3220.
9. COMPUTER SOFTWARE REQUIREMENTS
G3-6ED will compile and execute in FORTRAN IV Monitor Systems. Standard systems and I-O assignments are used, and two scratch tapes or other peripheral storage devices may be used.
10. REFERENCES
a. Included in package:
R. E. Malenfant, "G3: A General Purpose Gamma-Ray Scattering Code," LA-5176 (June 1973).
Informal Memo from R. E. Malenfant, Los Alamos Scientific Laboratory, November 8, 1979.
J. K. Warkentin, "Utilization Instructions for Operation of the GGG Program on the IBM 360/195 Computer," RRA-N7710 (Oct. 1977).
b. Background information:
G. H. Anno and J. K. Witthaus, "G-33, Code for Computing Gamma Ray Scattering," EAD-119, AN-COMP-196 (Feb. 1964).
The document package from CCC-48/QAD may give helpful information: LA-3573 and NASA TM-X-1397.
11. CONTENTS OF CODE PACKAGE
Included are the referenced document and one (1.2MB) DOS diskette which contains the source codes and input and output for sample problems.
12. DATE OF ABSTRACT
January 1968; updated July 1981, March 1985, October 1991.
KEYWORDS: GAMMA-RAY; KERNEL; COMPLEX GEOMETRY; SINGLE SCATTERING