**1. NAME AND TITLE**

GGG-GP: Kernel Integration Code System -- Multigroup Gamma-Ray Scattering Using the GP
Buildup Factor.

The present version is based on CCC-075/G^{3}-075 contributed by Los Alamos National Laboratory,
Los Alamos, N.M. The code was modified to accommodate the ANS-6.4.3 1988 buildup factor
compilation (26 materials).

**2. CONTRIBUTOR**

TU Electric, Glen Rose, Texas.

**3. CODING LANGUAGE AND COMPUTER**

Fortran 77; IBM PC.

**4. NATURE OF PROBLEM SOLVED**

GGG-GP estimates 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, uncollided result. Although GGG-GP is basically a single-scatter calculation,
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 buildup.

**5. METHOD OF SOLUTION**

GGG-GP employs the FASTER geometry routines to define region boundaries with the general
quadric equation. The buildup factor is computed from the coefficients using the Geometric
Progression (GP) fitting function. A subroutine was added to compute flux-to-dose rate conversion
factors for arbitrary photon energies based on standard curve fit parameters.

**6. RESTRICTIONS OR LIMITATIONS**

2The code can treat up to 20 source points, 30 source energies, 30 scatter-energy intervals, 400
geometry shield regions, 50 material compositions and as many detectors as desired.

**7. TYPICAL RUNNING TIME**

The sample problem (as tested at RSIC) took 2 hours and 22 minutes on an IBM PC/XT with a
math co-processor (compiler was RM/Fortran Version 2.42 under DOS 3.3).

**8. COMPUTER HARDWARE REQUIREMENTS**

The code runs on an IBM PC with a math co-processor.

**9. COMPUTER SOFTWARE REQUIREMENTS**

The code was tested using RM/Fortran Version 2.42 Fortran 77 compiler running under DOS 3.3
operating system. The IBM PC version was compiled by TU Electric using the IBM Professional
Fortran Version 1.00.

**10. REFERENCES**

**a. Included in the documentation:**

J. K. Warkentin. "GGG-GP Notes," informal document (November 2, 1990).

J. K. Warkentin. "Utilization Instructions For GGG-GP - A PC Version Of GGG With Geometric Progression Buildup Factors," informal document (November 1, 1990).

R. E. Malenfant, "G^{3}: A General Purpose Gamma-Ray Scattering Code," LA-5176 (1973).

**b. Background information:**

Y. Harima, Y. Sakamoto, S. Tanaka, and M. Kawai, "Validity of the Geometrical Progression
Formula in Approximating Gamma-Ray Buildup Factors," *Nucl. Sci. Eng.* 94, 24-35 (September
1986).

D. K. Trubey, "New Gamma-Ray Buildup Factor Data for Point Kernel Calculations: ANS-6.4.3 Standard Reference Data," ORNL/RSIC-49 (September 1988).

Y. Sakamoto and S. Tanaka, "QAD-CGGP2 and G33-GP2: Revised Versions of QAD-CGGP and
G33-GP Codes with Conversion Factors from Exposure to Ambient and Maximum Dose Equivalents,"
JAERI-M 90-110 (June 1990).

**11. CONTENTS OF CODE PACKAGE**

Included are the referenced documents and one DS/HD (1.2MB) DOS diskette.

**12. DATE OF ABSTRACT**

November 1990.

**KEYWORDS:** GAMMA-RAY; KERNEL; COMPLEX GEOMETRY; COMBINATORIAL GEOMETRY; MICROCOMPUTER