A SOURCE-ENERGY INTEGRATION PROGRAM DESIGNED TO OPERATE ON THE NGM CODE OUTPUT,

The Los Alamos Scientific Laboratory LASL is preparing a Neutron-Gamma Monte Carlo NGM transport code that will provide differential data for use in mapping the initial radiation environment created by a nuclear detonation. The NGM output provides fluxes at a series of detectors, normalized to one neutron which leaves the source in the given source-energy solid-angle group. By appropriately weighting the output and integrating it with respect to the variables, the radiation field of given weapons can be mapped. A set of codes has been generated at the US Army Nuclear Defense Laboratory to integrate the fluxes over the variables source energies and angles, detector energies, angles, and times, with appropriate weighting where necessary to provide input for special problems. This report describes a digital computer program written for the GE 225 computer 16K core storage and 6 magnetic tape drives in the General Assembly Program GAP language. The program integrates the LASL NGM radiation transport code differential flux output with the source-energy variable weighted by a user-supplied function. The resultant output is the flux at the detectors due to the user-supplied source-energy spectrum. The method of performing the weighted source-energy integration operation and the use of checksums to minimize error are given through the use of a flow diagram with complementary textual description, and the GAP source-deck listing. The method of running the program and how to respond to the error signals is also described. Author