1. NAME AND TITLE

ALBEDO/ALBEZ: Calculates Attenuation of Radiation in Single and Double Bends.

2. CONTRIBUTOR

NUKEM GmbH, Alzenau, Federal Republic of Germany.

3. CODING LANGUAGE AND COMPUTER

Fortran 77; IBM PC.

4. NATURE OF PROBLEM SOLVED

The programs ALBEDO and ALBEZ calculate the attenuation of scattered radiation in straight or bent air ducts for gamma-ray radiation in the range 0.1 - 3 MeV and fast neutrons in the range 0.1 - 14 MeV. ALBEDO treats straight ducts and ducts with one bend; ALBEZ treats ducts with two bends.

5. METHOD OF SOLUTION

In the case of gamma-ray radiation, the theory is based on the Compton effect. The energy and angle dependency of the energy of the scattered photons and the albedo-factors for the scattering is based on generally available literature. In the case of neutrons, the programs are valid only for fast neutrons. This range is due to the availability of the albedo factors in literature which describe the energy and angle dependencies of the scattered fast neutrons. The loss of energy of the neutrons due to scattering at the surface is neglected.

6. RESTRICTIONS OR LIMITATIONS

The program is restricted to gamma-ray radiation in the energy range .1 - 3 MeV. For fast neutrons, the range is 0.1 to 14 MeV. The albedos used in the codes are valid only for concrete ducts.

7. TYPICAL RUNNING TIME

Running time is dependent on the division of source surface, scattering surfaces and receptor surface. ALBEDO runs in a few seconds using the sample input as provided. ALBEZ runs for about a minute on the sample case. The codes were tested at RSIC on an IBM PC/XT running at 4.7 megahertz with a math co-processor.

8. COMPUTER HARDWARE REQUIREMENTS

IBM PC and compatibles. A math coprocessor is not required.

9. COMPUTER SOFTWARE REQUIREMENTS

The code was written in Fortran 77 and tested under PC-DOS (IBM PC). An executable file produced by the MSFORT Version 3.31 compiler is included.

10. REFERENCE

A. Baran and M. Grun, "ALBEDO, ALBEZ: PC-Programs for the Calculation of the Attenuation of Radiation in Single and Double Bends," NUKEM GmbH informal document (January 10, 1990).

11. CONTENTS OF CODE PACKAGE

Included are the referenced document and one (360 K) DOS diskette.

12. DATE OF ABSTRACT

August 1990.