1. NAME AND TITLE
S3: Kernel Integration Code System--Multigroup Gamma-Ray Scattering.
2. CONTRIBUTORS
Westinghouse Electric Corporation, Bettis Atomic Power Laboratory, West Mifflin, Pennsylvania.
Duquesne Light Company, Shippingport, Pennsylvania.
Eagle Research Group, Inc., Arlington, Virginia.
Los Alamos National Laboratory, Los Alamos, New Mexico.
3. CODING LANGUAGE AND COMPUTER
Fortran IV; CDC. Fortran 77; Vax and Microcomputer.
4. NATURE OF PROBLEM SOLVED
GGG (G3) is the generic designation for a series of computer programs that enable the user to estimate gamma-ray scattering from a point source to a series of point detectors. Program output includes detector response due to each source energy, as well as a grouping by scattered energy in addition to a simple, unscattered beam result. Although G3 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. G3 evaluates scattering effects in those situations where more exact techniques are not economical.
G3 was revised by Bettis and the name was changed to indicate that it was no longer identical to the G3 program. The name S3 was chosen since the scattering calculation has three steps: calculation of the flux arriving at the scatterer from the point source, calculation of the differential scattering cross section, and calculation of the scattered flux arriving at the detector.
5. METHOD OF SOLUTION
S3 evaluates the uncollided flux at specified scatter points and multiplies it by the product of the differential cross section for scattering toward the detector point and the number of electrons in the elemental volume associated with the scatter point, which is assumed to be at the center of the elemental volume. Attenuation through materials between the scatter point and the detector point is characteristic of the degraded energy as determined by the incident energy, the scattering angle, and the angle-energy relationships.
Detector response is recorded as a function of incident and scattered energy both with and without application of buildup on the path between the scatter point and the dose point. Conversion factors can be used to obtain results in any desired units.
Arrival intensities, energies, and incident-direction cosines are stored to eliminate recalculation for subsequent detector locations.
6. RESTRICTIONS OR LIMITATIONS
The scatter volume, which is superimposed on the main problem geometry description, must lie physically within what LA-5176 describes as an "inside zone" of the main problem geometry. Otherwise, the ray-trace from points in the scatter volume to the final detector points may be incorrect.
7. TYPICAL RUNNING TIME
On the Vax 8600 all of the sample problems required less than one minute of CPU time. On the Zenith Z100 with a math coprocessor, sample case 6 took almost an hour to run. On the IBM PC/XT without a math coprocessor, sample cases 3, 4 and 5 required about an hour each, while sample case 6 ran for about 5 hours.
8. COMPUTER HARDWARE REQUIREMENTS
The code is operable on the CDC 6600, Vax 11, Vax 8600, Zenith Z100, IBM PC and IBM PC/XT computers.
9. COMPUTER SOFTWARE REQUIREMENTS
A FORTRAN IV compiler is required for the CDC 6600 version, and ECS is necessary for the program to run efficiently. The VMS Fortran compiler Version 4 was used for the Vax version on the 8600 running VMS 4.5. The Microsoft Fortran 77 compilers, V3.20 and V3.31 have been used to compile the code on the Z100 under MS-DOS 2.1 and 2.2.
10. REFERENCES
R. L. Donovan, "Transmittal of the Micro S3 Code Package," Informal Notes (April 1986).
S. F. LaVie, "Transmittal of the SSSVAX Code Package," Informal Notes (June 1985).
O. J. Wallace, "Transmittal of the S3 Code Package," Informal Notes (June 1978).
R. E. Malenfant, "G3: A General Purpose Gamma-Ray Scattering Program," LA-5176 (June 1973).
11. CONTENTS OF CODE PACKAGE
Included are the referenced documents and one (1.2MB) DOS diskette which contains the source codes and sample problem input. Three DS/DD diskettes are required for the C version.
12. DATE OF ABSTRACT
January 1982, March 1988.
KEYWORDS: POINT SOURCE; KERNEL; GAMMA-RAY; MULTIGROUP; COMPLEX GEOMETRY; SINGLE SCATTERING