Quality assurance in optical and electro-optical engineering: Edited by L.R. Baker Proceedings of the Society of Photo-optical Instrumentation Engineers, Volume 73, 1976, pp 144, $35

Abstract

An analogue research-level, particle transport, Monte Carlo code for studying the attenuation and leakage of gamma ray photons in simple, multilayer, shielding configurations, originally written for conventional (i.e. serial) computers, is modified and re-written to run efficiently on the AMT DAP-610 highly parallel computer. The philosophy and algorithms adopted in transferring the code to the parallel machine are described. Two illustrative problems are solved using realistic cross-section data, involving a 9 MeV source of gamma photons in a lead-void-water sphere and slab. Integral quantities, such as fraction of particles absorbed and escaped, and differential quantities, such as flux distributions and leakage spectra, computed by the DAP parallel code, are presented in tables and graphs. These results are compared with those from the corresponding serial Monte Carlo code and also with an independent, deterministic, finite element method transport code. For equivalent calculations, the CPU times on the DAP and a number of serial computers (i.e. ICL-3900, CRAY XMP/28 in scalar mode, and VAC 11/750) are compared, and the resulting speedup factors quoted.