1. NAME AND TITLE

K019: Shield Thickness Calculation Program for Space Vehicles.

This code package is retained by RSIC to preserve space technology developed in the 1960s.

2. CONTRIBUTOR

NASA Manned Spacecraft Center, Houston, Texas.

3. CODING LANGUAGE AND COMPUTER

FORTRAN IV; IBM 360/75.

4. NATURE OF PROBLEM SOLVED

Shield thickness information is computed for use as input to codes which compute proton doses at points interior to an occupied spacecraft with complex shield geometry. For each detection point considered, the shield thicknesses computed are along rays emanating outward from the point, so that, in effect, all possible directions from which penetrating radiation could come are considered.

5. METHOD OF SOLUTION

Detection points within a complex structure are examined to find the thickness of shielding material present along rays directed from each point to the exterior of the structure. The ray directions for each point are such that they intersect the center equal areas on a unit sphere with origin at the point. For this purpose, the area of the unit sphere may be divided into 80, 320, 720, or 1280 smaller, non-overlapping areas of equal size. The complex structure may have shielding geometry described by combinations of hexahedrons, cylinders, spheres, hemispheres, and cones. Provision is also allowed for the presence of up to six phantom men in the structure, with arms and legs of each phantom in arbitrary positions. The detection points can be arbitrarily located within the structure, even inside a shield or phantom component. The thickness of shield material (in inches) along each ray is determined and expressed in terms of thickness (in g/cm^2) of some standard material such as aluminum. The total equivalent shield thickness (g/cm^2) along each ray is the output of the program. This information is output for each detector point considered.

6. RESTRICTIONS OR LIMITATIONS

Maximum number of materials 152

Maximum number of dose points 50

Maximum number of dose points in cylindrical or hemispherical components of a phantom 5

Maximum number of dose points in hexahedron components of a phantom 5

7. TYPICAL RUNNING TIME

Estimated running time of the packaged sample problem: 5 minutes.

8. COMPUTER HARDWARE REQUIREMENTS

The code was originally designed for the IBM 7090, then was re-programmed and has been run on the UNIVAC 1107 and the IBM 360/75. Packaged version is for the latter computer using standard I-O and 2 pool tapes or direct access devices.

9. COMPUTER SOFTWARE REQUIREMENTS

The code is operable on the IBM 360/75 Operating System using OS-360 Fortran H Compiler.

10. REFERENCE

C. F. Malone, "Program K019, Shield Thickness Calculation Program - Volume I, Computer Users Manual," NASA-MSC-3066 (May 1965).

11. CONTENTS OF CODE PACKAGE

Included are the referenced document and one (1.2MB) DOS diskette which contains the source code and input and output for a sample problem.

12. DATE OF ABSTRACT

May 1969; updated July 1981.

KEYWORDS: PATH LENGTHS