1. NAME AND TITLE
ARC: Aircraft Radiation Transport Code System, Crew Dose Calculation.
AUXILIARY ROUTINES
MEVDP: Modified Elemental Volume Dose Program (to compute the ray array for the aircraft using the extended form of subroutine ORDER).
MEVDP is a modified version of CCC-157/MEVDP. CCC-179/ATR is a useful related code/data package.
2. CONTRIBUTOR
Radiation Research Associates, Inc., Fort Worth, Texas.
3. CODING LANGUAGE AND COMPUTER
FORTRAN IV; CDC 6600.
4. NATURE OF PROBLEM SOLVED
ARC is a radiation transport program which calculates the effectiveness of the shielding provided by an aircraft while performing either a constant g maneuver or a constant radius turn maneuver in the vicinity of a nuclear weapon detonation. ARC computes the radiation doses (in rads) at an inside detector for neutrons, secondary gamma rays, and fission product gamma rays. ARC computes the delayed fission-product gamma-ray dose inside the aircraft as a function of time after detonation. The problem is continued until certain specified cut-off parameters are reached. If the aircraft is intercepted by the shock front, the time of arrival and peak overpressure are printed.
5. METHOD OF SOLUTION
ARC computes the aircraft position and the resulting radiation dose by proceeding through several incremental time steps and accumulating the dose over these steps. Thus, it uses a numerical integration scheme to evaluate the radiation at the aircraft (both initial radiation and fission product or delayed radiation), and the resultant doses.
There is an option to use the neutron and secondary gamma-ray output from the CCC-179/ATR code rather than the built-in neutron and secondary gamma-ray environment from a TN source.
6. RESTRICTIONS OR LIMITATIONS
The problem begins at time t = 0.0, and all events must occur after this time. The aircraft maneuver can begin before the detonation, however. ARC assumes a uniform air density equal to the value read in. No correction is made for non-uniform air. The user is expected to input an average air density applicable to the altitudes expected in the problem. This should not result in large errors for most problems of interest.
7. TYPICAL RUNNING TIME
The sample problem provided with program ARC was run by the contributor on CDC 6600, IBM 360/40 and IBM 370/165 computers for comparison purposes and the following results were obtained:
To execute sample problem Time
CDC 6600 2.2 System Seconds
IBM 360/40 140 Clock Seconds
IBM 370/165 2 Seconds (CPU + IO)
To compile program ARC: Time
CDC 6600 28.2 Seconds
IBM 360/40 580 Clock Seconds
IBM 370/165 14 Seconds (CPU + IO)
8. COMPUTER HARDWARE REQUIREMENTS
ARC is operable on the CDC 6600 computer.
9. COMPUTER SOFTWARE REQUIREMENTS
The extended CDC FORTRAN compiler was used for the packaged code. Changes required for the IBM conversion are included in the package but were not implemented by RSIC.
10. REFERENCES
a. Included in the documentation:
L. G. Mooney, C. W. Marslett, and R. L. Swanson, "Aircraft Radiation Code: ARC," DNA 3110F; AD 763751 (April 1973).
b. Background information:
B. Liley and S. C. Hamilton, "Modified Elemental Volume Dose Program (MEVDP)," AFWL-TR-69-68 (August 1969).
R. J. Harris, Jr., J. A. Lonergan, and L. Huszar, "Models of Radiation Transport in AirThe ATR Code," DNA 2803I (May 1972).
L. Huszar, L. J. Nesseler, and W. A. Woolson, "User's Guide to Version 2 of ATR (Air Transport of Radiation)," DNA 3144Z (SAI-73-534-LJ) (April 1973).
11. CONTENTS OF CODE PACKAGE
Included are the referenced document (10.a) and one (1.2MB) DOS diskette which contains the source code and sample problem input and output.
12. DATE OF ABSTRACT
August 1973; updated July 1975.
KEYWORDS: KERNEL; NUMERICAL INTEGRATION; NEUTRON; GAMMA-RAY; AIR TRANSPORT; WEAPONS RADIATION; COMPLEX GEOMETRY; TIME-DEPENDENT; RADIATION ENVIRONMENT