1. NAME AND TITLE
QADMOD-GP: Point Kernel Gamma-Ray Shielding Code With Geometric Progression
TU Electric, Glen Rose, Texas.
3. CODING LANGUAGE AND COMPUTER
Fortran 77; IBM PC.
4. NATURE OF PROBLEM SOLVED
QADMOD-GP is a PC version of the mainframe code CCC-396/QADMOD-G, a point-kernel
integration code for calculating gamma ray fluxes and dose rates or heating rates at specific detector
locations within a three-dimensional shielding geometry configuration due to radiation from a volume-distributed source.
5. METHOD OF SOLUTION
QADMOD-GP calculates gamma-ray fluxes, dose rates, or heating rates at discrete locations within
a complex source-geometry configuration by representing a volume-distributed source by a number
of point isotropic sources and computing the distances through all regions traversed by the line-of-sight
from the source points to a desired receiver point. From these distances and the characteristics of the
materials within them, energy-dependent exponential attenuation factors and energy-dependent buildup
factors for gamma-rays are applied to calculate the direct gamma-ray dose and the gamma-ray dose
with buildup. Like QADMOD-G, QADMOD-GP employs the FASTER geometry routines to define
region boundaries with the general quadric surface equation. Additional features of the PC version are
the following: 1) use of the geometric progression buildup factors; 2) addition of subroutine to allow
use of updated mass attenuation coefficients (without coherent scattering); 3) addition of subroutine
to compute flux-to-dose rate conversion factors for arbitrary photon energies; 4) increase of the
number of allowable computed source point locations (from 500 to 3,000); 5) increase the exponential
function minimum (from -180.218 to -87.0) in KERNEL to avoid underflows; 6) installation of a "card
image" routine to print formatted input data at the beginning.
6. RESTRICTIONS OR LIMITATIONS
The code can treat up to 300 shielding regions, 100 material compositions, and as many detectors
7. TYPICAL RUNNING TIME
On the IBM PC/XT with a math co-processor, the sample problem took about 1 minute.
8. COMPUTER HARDWARE REQUIREMENTS
QADMOD-GP runs on the IBM PC and compatibles with a math co-processor.
9. COMPUTER SOFTWARE REQUIREMENTS
A Fortran 77 compiler is required. The IBM Professional Fortran Version 1.0 compiler was used
by TU Electric to create the executable program. Alternatively, The RM/Fortran compiler version
2.42 can be used.
J. K. Warkentin, "QADMOD-GP Notes," Informal notes (November 2, 1990).
J. K. Warkentin, "Utilization Instructions For QADMOD-GP -- A PC Version Of QADMOD-G With Geometric Progression Buildup Factors," (November 1, 1990).
J. H. Price and W. G. M. Blattner, "Utilization Instructions for QADMOD-G," RRA-N7914
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).
11. CONTENTS OF CODE PACKAGE
Included are the referenced document and one (1.2 MB) DOS diskette.
12. DATE OF ABSTRACT
KEYWORDS: KERNEL; GAMMA-RAY; COMPLEX GEOMETRY; MICROCOMPUTER