1. NAME AND TITLE

ALGAM: Monte Carlo Estimation of Internal Dose from Gamma-Ray Sources in a Phantom Man.

DATA LIBRARY

HPICE: Evaluated Photon Interaction Data in ENDF Format.

ALGAM was originally packaged in 1973; was updated in 1975; reviewed in 1981. The HPICE data (ENDF/B-III) is packaged in RSIC as DLC-7C.

2. CONTRIBUTOR

Oak Ridge National Laboratory, Oak Ridge, Tennessee.

3. CODING LANGUAGE AND COMPUTER

FORTRAN IV, Assembly Language; IBM 360/75/91.

4. NATURE OF PROBLEM SOLVED

ALGAM computes dose deposited by gamma rays from an external or internal source in various sections of a phantom approximating the body of a man.

5. METHOD OF SOLUTION

The body is considered to be made up of three kinds of tissue: soft tissue, bone, and lung. The phantom is divided into a number of sections and each is given a reasonably typical tissue composition. The user can specify a source arbitrarily through a subroutine. Monte Carlo calculations using the OGRE System (see CCC-46) are employed for particle transport. In addition to options available in OGRE, Woodcock's scheme of the artificial "nothing" cross section is employed to make the total cross section a constant throughout the phantom. Doses are determined from photon energy deposited at each interaction point.

6. RESTRICTIONS OR LIMITATIONS

The user must provide his own SOURCE routine; he must provide a pseudo random number generator, FUNCTION FLTRNF (dummy), appropriate to his own computer.

7. TYPICAL RUNNING TIME

To run histories of 50,000 photons would take between 3 minutes and 15 minutes on an IBM 360/91 computer depending upon the initial energy of the photons. The code occupies about 185,000 bytes of storage in an IBM 360/91.

Estimated running time of the packaged sample problem on the IBM 360/91: 4 minutes.

8. COMPUTER HARDWARE REQUIREMENTS

IBM 360, Standard I-O and 1 tape/disk unit.

9. COMPUTER SOFTWARE REQUIREMENTS

The code is operable on the IBM 360/75/91 Operating System using OS-360 Fortran H Compiler. A random number generator is required and is supplied in Assembly Language. A table of cross sections is required and DLC-7C is included on the master tape.

10. REFERENCES

G. G. Warner and A. M. Craig, Jr., "ALGAM, A Computer Program for Estimating Internal Dose for Gamma-Ray Sources in a Man Phantom," ORNL-TM-2250 (June 1968).

G. G. Warner and W. S. Snyder, "Dose from Gamma-Ray Sources," ORNL Mathematics Division Annual Progress Report, December 31, 1972, ORNL-4851, pp. 29-31.

M. J. Cook, W. S. Snyder, and G. G. Warner, "Estimates of Dose to Red Bone Marrow from Monoenergetic Sources of Photons in Lungs and Other Organs," Health Physics Division Annual Progress Report, July 31, 1970, ORNL-4584, pp. 200-202.

W. S. Snyder, H. L. Fisher, Jr., Mary R. Ford, and G. G. Warner, "Estimates of Absorbed Fractions for Monoenergetic Photon Sources Uniformly Distributed in Various Organs of the Heterogeneous Phantom" MM/MIRD Pamphlet No. 5 (Aug. 1969, Vol. 10).

11. CONTENTS OF CODE PACKAGE

Included are the referenced documents and 1 DOS diskette which contains the source codes, data library, and sample problem input and output.

12. DATE OF ABSTRACT

February 1972; revised December 1984.

KEYWORDS: MONTE CARLO; INTERNAL DOSE; GAMMA-RAY; PHANTOM