1. NAME AND TITLE
SMAUG-13: Calculation of Neutron and Prompt Gamma-Ray Doses Resulting from an Atmospheric Nuclear Detonation.
2. CONTRIBUTOR
Air Force Weapons Laboratory, Kirtland Air Force Base, New Mexico.
3. CODING LANGUAGE AND COMPUTER
FORTRAN IV; CDC 6600.
4. NATURE OF PROBLEM SOLVED
Using mass integral scaling of infinite, homogeneous air data sets made through the use of the discrete ordinates code CCC-254/ANISN-ORNL, SMAUG calculates the neutron and the prompt gamma-ray (including neutron-induced secondary gamma-ray) fluences, spectra, and doses at user-selected receiver points. Requiring minimal input preparation effort on the user's part, SMAUG provides very rapid dose solutions in a readable format. Neutron results which are computed include: fluence, spectrum in 22 energy bands, energy fluence (MeV/cm2), mean energy, tissue dose, midline dose in a 30-cm diameter tissue-equivalent phantom, and silicon dose. Gamma-ray results which are computed include: fluence, spectrum in 18 energy bands, energy fluence, mean energy, tissue dose, midline phantom dose, air dose (Roentgens) and silicon dose. The discrete ordinates data is taken from ORNL-4464.
5. METHOD OF SOLUTION
The information in the ANISN- and SORS-computed SMAUG data bases has been reduced to a series of 419 six-constant empiric transmission functions of the areal density between the source and the receiver. SMAUG performs 12-point Gauss-Legendre quadrature of the air density between the source and the receiver using the exponential air model in the "U.S. Standard Atmosphere, 1962" to compute areal density. The transmission functions are evaluated to scale the infinite, homogeneous air results to the problem at hand.
SMAUG uses a 9-band neutron source spectrum and prints the neutron receiver spectrum in 22 bands. The gamma-ray source spectrum consists of 10 bands; the receiver spectrum consists of 18 bands.
For depths beyond the range spanned by the data bases, SMAUG performs simple exponential extrapolation for each source-receiver band.
6. RESTRICTIONS OR LIMITATIONS
Maximum depth in air is 600 g/cm2. Maximum altitude for either source or receiver is 50,000 meters. No correction is made for the air/ground interface.
7. TYPICAL RUNNING TIME
Run time depends on the complexity of the problem; however, for a typical problem, one receiver point solution is obtained in approximately 1.5 seconds of CDC 6600 central processor time.
8. COMPUTER HARDWARE REQUIREMENTS
SMAUG was written in ANSI FORTRAN to be as machine-independent as possible. It was developed and run on the AFWL CDC 6600 and should be capable of running on any scientific computer with adequate core size. When compiled on the AFWL CDC 6600, SMAUG required 18,650 words of central memory (44,200 octal). It uses one tape unit to dump or load the labeled COMMON blocks.
9. COMPUTER SOFTWARE REQUIREMENTS
A FORTRAN compiler is required. A FORTRAN cube-root function, CUBRT, is included with the program.
10. REFERENCES
a. Included in the documentation:
H. M. Murphy, "SMAUG, A Computer Code to Calculate the Neutron and Gamma Prompt Dose Environment in the Vicinity of an Atmospheric Nuclear Detonation," AFWL-TR-72-2 (November 1972).
H. M. Murphy, Jr., "A User's Guide to the SMAUG Computer Code," AFWL-TR-72-3 (May 1972).
b. Background information:
E. A. Straker and M. L. Gritzner, "Neutron and Secondary Gamma-Ray Transport in Infinite Homogeneous Air," ORNL-4464 (December 1969).
11. CONTENTS OF CODE PACKAGE
Included are the referenced documents and 1 DOS diskette which contains the source code and sample problem input, plus output from the sample problem.
12. DATE OF ABSTRACT
August 1975.
KEYWORDS: NEUTRON; GAMMA-RAY; PARAMETRIC MODELS; AIR TRANSPORT