1. NAME AND TITLE

FASTER III: Monte Carlo Neutron and Photon Transport Code System in Complex Geometries.

FASTER III accepts neutron and secondary production cross sections in the ANISN-DOT format, e.g., output from POPOP4 (PSR-11). It incorporates numerous additions and modifications made to the earlier FASTER development (CCC-98) which is no longer being disseminated.

2. CONTRIBUTORS

A. R. T. Research Corporation, Los Angeles, California.

NASA Lewis Research Center, Cleveland, Ohio.

3. CODING LANGUAGE AND COMPUTER

FORTRAN IV; UNIVAC 1108 (A), IBM 360 (B).

The A Version includes changes necessary to also run on the CDC 6600.

4. NATURE OF PROBLEM SOLVED

FASTER III calculates neutron and/or photon transport for point, surface and/or volume detectors. Program capabilities include the use of multigroup or point value neutron cross sections, an approximate slowing down kernel for neutrons, calculation of secondary photon (or neutron) transport, multiple complex source descriptions, quadric, helical and/or toroidal surface geometries; simple input for spherical, cylindrical and regular three-dimensional geometries, a spherical exponential atmosphere model, correlated calculations with source and/or material changes; flux edits for birth region, order of scatter, scattering region, boundary crossing, and initial source group; angular fluxes by Legendre moments and/or solid angle bins; temporal fluxes by temporal moments and/or time bins; derivatives of fluxes with respect to region dimension changes; optimum shield mass distribution for multiple response constraints, arbitrary rotation and/or translation of sources and/or geometry, and numerous importance sampling options.

5. METHOD OF SOLUTION

FASTER III utilizes the Monte Carlo method for the generation and tracking of particles. Importance sampling is used in all of the decision processes. Usually, the entire spectrum of particle energies is treated simultaneously. Optionally, the code will treat a limited portion of the spectrum on each history.

6. RESTRICTIONS OR LIMITATIONS

Dynamic storage allocation is used. The limitation on problem size is based on available core.

7. TYPICAL RUNNING TIME

Typical running time: 0.1 second per collision for an energy-dependent particle.

Estimated running time of the packaged sample problem on the IBM 360/91: 24 seconds.

8. COMPUTER HARDWARE REQUIREMENTS

FASTER III was designed for machine-independent operation with approximately 60K (decimal) core (240K bytes) required for large, complex problems. Packaged versions operate on the IBM 360 (B) and the UNIVAC 1108 (A). Auxiliary storage is used only as required for particular problems, e.g., cross section library tape (optional), restart tape (optional), secondary source files.

Channel configuration is set by user through control cards and input data specifying logical designations to the program. Auxiliary equipment is normally limited to the printer with optional use of a card punch and/or Calcomp plotter.

9. COMPUTER SOFTWARE REQUIREMENTS

All parameters which may need changing for system compatibility can be changed in the main program. FASTER III functions under standard operating systems, e.g., 360/OS, 1108/EXECII and 8. Only standard library routines are used. Channel assignments are variable. Version A contains changes needed to implement the code system on the CDC 6600.

10. REFERENCES

R. M. Jordan, "FASTER-III, A Generalized-Geometry Monte Carlo Computer Program for the Transport of Neutrons and Gamma Rays," ART-45, Volumes I and II (December 1970).

T. M. Jordan, "FASTER, A FORTRAN Analytic Solution of the Transport Equation by Random Sampling," WANL-PP(LL)-010, Volume 9 (June 1967).

11. CONTENTS OF CODE PACKAGE

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

12. DATE OF ABSTRACT

June 1972; revised December 1984.