1. NAME AND TITLE
STREAM: A Three-Dimensional Cylindrical-Geometry Monte Carlo Ray Tracing Code for
Computing Light Transmission.
Air Force Weapons Laboratory, Kirtland Air Force Base, New Mexico.
3. CODING LANGUAGE AND COMPUTER
FORTRAN IV; CDC 7600.
4. NATURE OF PROBLEM SOLVED
STREAM theoretically tests light transmission through complex cylindrically symmetric SHIVA
chamber geometries. (SHIVA is a Z-pinch device used to produce hot dense radiating plasmas by the
ionization and J and B implosion of a short cylindrical foil.) If sufficient UV light is transmitted from
the ionized foil to the chamber insulator, the resulting ionization of the insulator may cause the
chamber to break down electrically.
5. METHOD OF SOLUTION
Three-dimensional cylindrical geometry with theta symmetry is used. Specular or diffuse
reflections or any combination of the two phenomena may be specified. Diffuse reflections can be
treated in several ways, for example, any distribution (isotropic or cosine distributions are standard)
is allowed, and it can be oriented around the surface normal or along the specular reflection angle.
Adsorption is calculated for each reflection, and it is a function of the angle of incidence, index of
refraction, and extinction coefficient. The output includes relative intensity crossing designated
surfaces in the geometry. The input intensity is unity. An optional output file is available for 2-D
microfiche plotting of successful (hits on the insulator) photon paths.
6. RESTRICTIONS OR LIMITATIONS
7. TYPICAL RUNNING TIME
No study has been made by RSIC of typical running times for STREAM.
8. COMPUTER HARDWARE REQUIREMENTS
STREAM is operable on the CDC 7600 computer.
9. COMPUTER SOFTWARE REQUIREMENTS
A FORTRAN IV compiler is required.
J. A. Justice, "STREAM: A Three-Dimensional Monte Carlo Ray Tracing Code in Cylindrical
Geometry," AFWL-TR-76-206 (February 1977).
11. CONTENTS OF CODE PACKAGE
Included are the referenced document and one (1.2MB) DOS diskette which contains the source
code and STREAM data.
12. DATE OF ABSTRACT
August 1979; reviewed March 1982.
KEYWORDS: COMPLEX GEOMETRY; MONTE CARLO; CYLINDRICAL GEOMETRY; LIGHT