**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.

**KEYWORDS: ** ADJOINT; MOMENTS METHOD; GAMMA-RAY; INFINITE MEDIUM