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The report presents a code, developed by the author, that predicts neutron and gamma fluences (or does), including neutron induced gammas, in an exponential atmosphere for burst altitudes between 7 and 100 kilometers. The problem was solved by using the diffusion equation, with separation of virgin and scattered particles, in a nonorthogonal coordinate system. The diffusion equation in this coordinate system was approximated by a nine point difference equation and the resulting matrix equation was solved by use of a block tri- diagonal algorithm. The resulting computer code, in FORTRAN Extended, was written to calculate the survivability of up to 100 aircraft or space vehicles in addition to the calculation of fluences (doses).

The report contains the description of a computer code which calculates effects due to a nuclear burst, and determines the survivability of up to 100 selected vehicle positions. The effects calculated are those due to X-rays, neutrons, gammas, induced gammas, blast, and thermal. The code accepts as input; the number and spectra of the nuclear bursts; the vulnerability of the vehicles (one type at a time) to the various effects; the mission profile (initial positions and velocity vectors). The code then computes the level of each effect from each burst at each target position. If any effect level exceeds the vehicle's given vulnerability, that vehicle is assumed to be killed. In the case of blast only a probability of survival may be computed rather than a kill/no kill determination. The code is written in FORTRAN Extended for the CDC 6600 computer located at Wright-Patterson Air Force Base, Ohio. The code requires 290 seconds of computer time for each burst to be analyzed, and a central core of 156000 octal regardless of the number of bursts. This report contains detailed descriptions of the calculation of effects due to neutrons and gammas. (Modified author abstract), See also Volume 2, AD-767 889, Volume 1, AD-767 888, and Volume 5, AD-767 894.