Probabilities for lattice integral transport

A computer routine was written to enable an efficient, yet accurate, interpolation of basic probabilities required in integral transport calculations of single lattice, as well as multicell structures. These are: a) Transmission and escape probabilities for layers in slab, cylindrical, and spherical geometries, b) Dancoff probabilities for cylinders in square and hexygonal lattices. The tables within which the routine interpolates contain remainders between accurate probabilities to respective analytical approximations. There are ≅ 4000 entries for a cylindrical or spherical geometry, 50 for slab geometry. The accuracy is a few tenth of a percent, usually much lower, relative error for all the probabilities. The range of optical thicknesses covered is 0 to 20. All the probabilities required for a given layer may be generated on a CRAY-XMP in a 5.10-6 s. A single Dancoff probability can be generated in ≅ 2.7.10-6 s. (author) 7 refs