1. NAME AND TITLE

BRHGAM: Monte Carlo Estimation of Absorbed Dose from X-Ray Sources in Phantom Man.

2. CONTRIBUTOR

Oak Ridge National Laboratory, Oak Ridge, Tennessee.

3. CODING LANGUAGE AND COMPUTER

Fortran IV, Assembler language; IBM 360/370.

4. NATURE OF PROBLEM SOLVED

BRHGAM is a Monte Carlo computer program which is utilized to calculate estimates of absorbed dose in several body organs of an adult human phantom. The source of radiation is a simulated external beam of X-rays in the energy range 20 to 150 keV.

BRHGAM was compiled from elements of ALGAM, a Monte Carlo computer code for estimating internal photon dose, and newly written sub-programs.

5. METHOD OF SOLUTION

Primarily, the code has been used with normally incident 4 x 4 cm collimated parallel monoenergetic photon beams of 30, 55, and 80 keV. By changing certain input parameters, the incident angle of the beam, the beam size, and the initial energy of the beam might be varied. With the output of the code, it is possible to obtain dose from a larger beam by adding together the data from a number of 4 x 4 beams.

BRHGAM has a main program which generally controls the flow of the code by initializing or terminating each step of the code. The main program also controls the beginning input, the beginning and ending of the history of each photon, the ending of all of the histories, and the final output.

6. RESTRICTIONS OR LIMITATIONS

The code was modified specifically for the situation of external rectangular beam sources of monoenergetic photons impinging on an adult human phantom next to a diagnostic table. No other configuration is permitted. Location of the table, the beam size, and the beam angle may vary from exposure to exposure, but not from run to run. Only the location of the beam impingement site may vary between runs.

7. TYPICAL RUNNING TIME

The sample problem took 5 minutes on the IBM 360/91.

8. COMPUTER HARDWARE REQUIREMENTS

BRHGAM is operable on the IBM 360/370 computers. It requires 138 K storage.

9. COMPUTER SOFTWARE REQUIREMENTS

Fortran H and Assembler compilers are required. The code uses standard I/O plus 1 additional storage unit.

10. REFERENCES

G. G. Warner, Informal Notes, (January 1974).

G. G. Warner, "BRHGAM: A Medical X-Ray Dose Estimation Program," ORNL-TM-4393 (October 1973).

11. CONTENTS OF CODE PACKAGE

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

12. DATE OF ABSTRACT

January 1982.