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RSIC CODE PACKAGE CCC-157



1. NAME AND TITLE

MEVDP: Primary Radiation Transport Code System Complex Geometry Computerized Anatomical Model Man.



MEVDP is a modification of EVDP, a code system developed to calculate primary radiation doses from protons and alpha particles associated with solar-flare particle events and the earth's trapped radiation for deep space and earth orbital missions.



DATA LIBRARIES

CAM: Computerized Anatomical Model Man Standing and Seated.



2. CONTRIBUTORS

Air Force Weapons Laboratory, Albuquerque, New Mexico.

Space Division, North American Rockwell Corp., Downey, California.

Martin Marietta Corporation, Denver, Colorado.



3. CODING LANGUAGE AND COMPUTER

FORTRAN IV; CDC 6600.



4. NATURE OF PROBLEM SOLVED

MEVDP generates ordered path-length areal densities for primary electron, electron-bremsstrahlung, and secondary particle radiation transport calculations. It also generates standard-material areal-density distribution functions for proton and heavy ionizing nuclear radiation. The primary and secondary areal-density functions can be used for particle transport calculations to compute emergent fluxes and energy deposition. The code system has been successfully run with the complex Apollo command and service modules and the lunar module, which are represented by 1000 elemental volume shield configurations.

The Computerized Anatomical Model Man is a detailed representation of the radiation transport properties of the human body. It is to be used for computation of the areal density distribution of specified locations in the body. This information is applicable to dose calculations in natural, weapon, reactor, and other radiation environments. The model has two configurations standing and seated. Over 2200 individual geometrical shapes have been used to depict the external conformation, the skeleton, and the principal organs. The exterior dimensions are those of the 50th percentile Air Force man; the skeleton and organs were scaled from life-size models to conform to the exterior. The model includes variations of material density and fractional composition by weight due to the principal chemical elements contained in muscle, bone, bone marrow, and organ tissue.



5. METHOD OF SOLUTION

MEVDP generates spatially oriented arrays of material type and associated thicknesses which are encountered by radiation traveling toward a dosimeter point within any complex geometrical shielding configuration. These thickness arrays are available in the order in which the incident rays encounter the different materials. The program computes the standard-material areal-density distribution function versus fractional solid angle for heavy charged particle dose computations. The code contains the source ray selection and geometrical options of the original EVDP, including the composite shield routine. These features have been modified and augmented by a subroutine to order the computed nuclear transport parameters. The ordered arrays can be used for electron and secondary transport calculations with the straight-ahead approximation.

To interface with MEVDP, the Computerized Anatomical Model Man conforms to two principal requirements. First, the geometrical configuration of the model has been established with combinations of the geometrical shapes recognized by MEVDP. These shapes are the hexahedron a figure comprised of six planar surfaces: right circular cylinder; sphere; hemisphere; right circular cone, truncated right circular cone and the ellipsoid - truncated by two or fewer parallel planes. Second, the card-image data that represent the standing and seated positions of the man are in the format required for operation with MEVDP. In addition to geometrical data, the identity of the shield a four-digit number, a three-digit number identifying the shield material, the material density, and a number indicating the number of individual shields comprising a composite shield are included.



6. RESTRICTIONS OR LIMITATIONS

None noted.



7. TYPICAL RUNNING TIME

No study has been made by RSIC of typical running times for MEDVP.



8. COMPUTER HARDWARE REQUIREMENTS

The code was designed for the IBM 360. The packaged version is operable on the CDC 6600, using a maximum of 8 tape units or other direct access devices.



9. COMPUTER SOFTWARE REQUIREMENTS

Standard FORTRAN IV compilers may be used.



10. REFERENCES

B. Liley and S. C. Hamilton, "Modified Elemental Volume Dose Program (MEVDP)," AFWL-TR-69-68 (March 1971).

P. G. Kase, "Computerized Anatomical Model Man," AFWL-TR-69-161 (January 1970).



11. CONTENTS OF CODE PACKAGE

Included are the referenced documents and one (1.2MB) DOS diskette which contains the source code, data libraries, and sample problem input. Output from the sample problems is printed in the documentation.



12. DATE OF ABSTRACT

February 1972; revised December 1984.



KEYWORDS: MODEL MAN; PHANTOM; COMPLEX GEOMETRY; ELECTRON; PROTON; PATH LENGTHS