1. NAME AND TITLE

ADJMOM-1: Adjoint Moments Method Gamma-Ray Transport Code System.

2. CONTRIBUTORS

National Bureau of Standards, Washington, D. C.

Science Applications, Inc., Huntsville, Alabama.

3. CODING LANGUAGE AND COMPUTER

FORTRAN IV; IBM 360/370.

4. NATURE OF PROBLEM SOLVED

ADJMOM-1 calculates the moments of the adjoint gamma-ray flux distribution in an unbounded medium. Angular characteristics of the source may be included.

5. METHOD OF SOLUTION

The linked integral equations of the moments of the adjoint gamma-ray flux are a function of energy, the spatial moment index, and the angular moment indices. The equations are solved numerically starting from the lowest energy and proceeding to higher energies. The source term is specified in terms of response function, and in angular response function. Gaussian integration procedures are used to evaluate part of the scattering integral.

6. RESTRICTIONS OR LIMITATIONS

The number of energies is limited to 400 and the number of spatial and angular moment index combinations is limited to 150. These parameters may be expanded to fill the available core.

7. TYPICAL RUNNING TIME

Running time is approximately proportional to the maximum number of solution energies and spatial and angular moment index combinations. The packaged sample problem was executed in 7 seconds on the IBM 360/91 computer.

8. COMPUTER HARDWARE REQUIREMENTS

ADJMOM-1 is operable on the IBM 360/370 computers. It should be easily converted to run on UNIVAC and CDC computers. It uses standard I-O units and a maximum of 3 additional direct-access devices. Core size is 220 K.

9. COMPUTER SOFTWARE REQUIREMENTS

A FORTRAN IV compiler is required.

10. REFERENCE

G. L. Simmons, "An Adjoint Gamma-Ray Moments Computer Code, ADJMOM-1," NBS Technical Note 748 (February 1973).

11. CONTENTS OF CODE PACKAGE

Included are the referenced document and one (1.2MB) DOS diskette which contains the source code and sample problem input and output.

12. DATE OF ABSTRACT

July 1975; updated July 1975.